In `AnimatedList`, AnimationController should forward when `_itemBuilder()` is called but not `insertItem()`

Steps to reproduce

See code example please.

Expected results

When I scroll to items outside screen, their animation should start forwarding.

Actual results

When I insert items into AnimatedList, their animations will forward immediately. This causes when I scroll to those items outside screen, they have no animation, since AnimationControllers have disposed after animation duration. https://github.com/flutter/flutter/blob/ddd6c8695084d6661574bf941b79e2eca252be58/packages/flutter/lib/src/widgets/animated_scroll_view.dart#L1135-L1137 What I wish is that when I scroll to other items, _itemBuilder will be called and their AnimationControllers should forward at this time. https://github.com/flutter/flutter/blob/ddd6c8695084d6661574bf941b79e2eca252be58/packages/flutter/lib/src/widgets/animated_scroll_view.dart#L1076-L1092

Code sample

```dart import 'package:flutter/material.dart'; void main() { runApp(const MyApp()); } class MyApp extends StatefulWidget { const MyApp({super.key}); @override State createState() => MyAppState(); } class MyAppState extends State { final listKey = GlobalKey(); @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( body: SafeArea( child: AnimatedList( key: listKey, itemBuilder: buildItem, ), ), floatingActionButton: FloatingActionButton( onPressed: () { listKey.currentState!.insertAllItems(0, 100); }, ), ), ); } Widget buildItem( BuildContext context, int index, Animation animation) { print(index); return KeepAliveWrapper( child: FadeTransition( opacity: animation, child: Container( height: 80, color: Colors.orange, child: Center(child: Text('Item $index')), ), ), ); } } class KeepAliveWrapper extends StatefulWidget { const KeepAliveWrapper({ super.key, this.keepAlive = true, required this.child, }); final bool keepAlive; final Widget child; @override KeepAliveWrapperState createState() => KeepAliveWrapperState(); } class KeepAliveWrapperState extends State with AutomaticKeepAliveClientMixin { @override Widget build(BuildContext context) { super.build(context); return widget.child; } @override void didUpdateWidget(covariant KeepAliveWrapper oldWidget) { if (oldWidget.keepAlive != widget.keepAlive) { updateKeepAlive(); } super.didUpdateWidget(oldWidget); } @override bool get wantKeepAlive => widget.keepAlive; } ```

Screenshots or Video

Screenshots / Video demonstration

**Expected:** When I scroll to those items outside screen, they start fading in. https://github.com/flutter/flutter/assets/73378246/a8531a9f-636e-44b4-91f8-12147041b3ef **In fact:** Animations have already completed. https://github.com/flutter/flutter/assets/73378246/4b6343cc-6193-4681-a5e8-3ea2a53d1448

Logs

```console [Paste your logs here] ```

Flutter Doctor output

Doctor output

```console [Paste your output here] ```

Thanks for the detailed report. I was able to replicate this in latest versions.

stable, master flutter doctor -v

``` [!] Flutter (Channel stable, 3.22.0, on macOS 12.2.1 21D62 darwin-x64, locale en-GB) • Flutter version 3.22.0 on channel stable at /Users/dhs/documents/fluttersdk/flutter ! Warning: `flutter` on your path resolves to /Users/dhs/Documents/Fluttersdk/flutter/bin/flutter, which is not inside your current Flutter SDK checkout at /Users/dhs/documents/fluttersdk/flutter. Consider adding /Users/dhs/documents/fluttersdk/flutter/bin to the front of your path. ! Warning: `dart` on your path resolves to /Users/dhs/Documents/Fluttersdk/flutter/bin/dart, which is not inside your current Flutter SDK checkout at /Users/dhs/documents/fluttersdk/flutter. Consider adding /Users/dhs/documents/fluttersdk/flutter/bin to the front of your path. • Upstream repository https://github.com/flutter/flutter.git • Framework revision 5dcb86f68f (5 days ago), 2024-05-09 07:39:20 -0500 • Engine revision f6344b75dc • Dart version 3.4.0 • DevTools version 2.34.3 • If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly to perform update checks and upgrades. [!] Xcode - develop for iOS and macOS (Xcode 12.3) • Xcode at /Applications/Xcode.app/Contents/Developer ! Flutter recommends a minimum Xcode version of 13. Download the latest version or update via the Mac App Store. • CocoaPods version 1.11.2 [✓] Chrome - develop for the web • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome [✓] VS Code (version 1.62.0) • VS Code at /Applications/Visual Studio Code.app/Contents • Flutter extension version 3.21.0 [✓] Connected device (5 available) • SM G975F (mobile) • RZ8M802WY0X • android-arm64 • Android 11 (API 30) • Darshan's iphone (mobile) • 21150b119064aecc249dfcfe05e259197461ce23 • ios • iOS 14.4.1 18D61 • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729 • ios • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator) • macOS (desktop) • macos • darwin-x64 • Mac OS X 10.15.4 19E2269 darwin-x64 • Chrome (web) • chrome • web-javascript • Google Chrome 98.0.4758.80 [✓] HTTP Host Availability • All required HTTP hosts are available ! Doctor found issues in 1 category. [!] Flutter (Channel master, 3.22.0-30.0.pre.11, on macOS 12.2.1 21D62 darwin-x64, locale en-GB) • Flutter version 3.22.0-30.0.pre.11 on channel master at /Users/dhs/documents/fluttersdk/flutter ! Warning: `flutter` on your path resolves to /Users/dhs/Documents/Fluttersdk/flutter/bin/flutter, which is not inside your current Flutter SDK checkout at /Users/dhs/documents/fluttersdk/flutter. Consider adding /Users/dhs/documents/fluttersdk/flutter/bin to the front of your path. ! Warning: `dart` on your path resolves to /Users/dhs/Documents/Fluttersdk/flutter/bin/dart, which is not inside your current Flutter SDK checkout at /Users/dhs/documents/fluttersdk/flutter. Consider adding /Users/dhs/documents/fluttersdk/flutter/bin to the front of your path. • Upstream repository https://github.com/flutter/flutter.git • Framework revision c90e18c6f5 (2 hours ago), 2024-05-09 20:32:11 -0700 • Engine revision c0917b14fc • Dart version 3.5.0 (build 3.5.0-138.0.dev) • DevTools version 2.36.0-dev.5 • If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly to perform update checks and upgrades. [!] Android toolchain - develop for Android devices (Android SDK version 30.0.3) • Android SDK at /Users/dhs/Library/Android/sdk ✗ cmdline-tools component is missing Run `path/to/sdkmanager --install "cmdline-tools;latest"` See https://developer.android.com/studio/command-line for more details. ✗ Android license status unknown. Run `flutter doctor --android-licenses` to accept the SDK licenses. See https://flutter.dev/docs/get-started/install/macos#android-setup for more details. [✓] Xcode - develop for iOS and macOS (Xcode 13.2.1) • Xcode at /Applications/Xcode.app/Contents/Developer • Build 13C100 • CocoaPods version 1.11.2 [✓] Chrome - develop for the web • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome [✓] IntelliJ IDEA Ultimate Edition (version 2021.3.2) • IntelliJ at /Applications/IntelliJ IDEA.app • Flutter plugin version 65.1.4 • Dart plugin version 213.7228 [✓] VS Code (version 1.62.0) • VS Code at /Applications/Visual Studio Code.app/Contents • Flutter extension version 3.29.0 [✓] Connected device (3 available) • Darshan's iphone (mobile) • 21150b119064aecc249dfcfe05e259197461ce23 • ios • iOS 15.3.1 19D52 • macOS (desktop) • macos • darwin-x64 • macOS 12.2.1 21D62 darwin-x64 • Chrome (web) • chrome • web-javascript • Google Chrome 109.0.5414.119 [✓] Network resources • All expected network resources are available. ! Doctor found issues in 1 category. [!] Xcode - develop for iOS and macOS (Xcode 12.3) • Xcode at /Applications/Xcode.app/Contents/Developer ! Flutter recommends a minimum Xcode version of 13. Download the latest version or update via the Mac App Store. • CocoaPods version 1.11.2 [✓] Chrome - develop for the web • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome [✓] VS Code (version 1.62.0) • VS Code at /Applications/Visual Studio Code.app/Contents • Flutter extension version 3.21.0 [✓] Connected device (5 available) • SM G975F (mobile) • RZ8M802WY0X • android-arm64 • Android 11 (API 30) • Darshan's iphone (mobile) • 21150b119064aecc249dfcfe05e259197461ce23 • ios • iOS 14.4.1 18D61 • iPhone 12 Pro Max (mobile) • A5473606-0213-4FD8-BA16-553433949729 • ios • com.apple.CoreSimulator.SimRuntime.iOS-14-3 (simulator) • macOS (desktop) • macos • darwin-x64 • Mac OS X 10.15.4 19E2269 darwin-x64 • Chrome (web) • chrome • web-javascript • Google Chrome 98.0.4758.80 [✓] HTTP Host Availability • All required HTTP hosts are available ! Doctor found issues in 1 category. ```

flutter / flutter