[Release] 4.0.0

[tanaynigam]

Xamarin OneSignal SDK Major Release 4.0.0

Check out the migration guide to update the OneSignal SDK from version 3.x.x to version 4.x.x

You can also read all of the API changes from the changelogs

Native version

• Updated OneSignal Android version to 4.7.1
• Updated OneSignal iOS version to 3.10.2

Namespace

• Updated the nuget package name and namespaces for the OneSignal SDK from Com.OneSignal to OneSignalSDK.Xamarin

Bindings

• iOS - Edited ApiDefinition to create Bindings from .aar file
• iOS - Updated Structs.cs for iOS native enums
• iOS - switched from .framework to .xcframework
• Android - Updated Project settings to use class parse instead of jar2xml as jar file parser
• Android - Updated Project settings to remove Java.Interop package

OneSignalSDK.Xamarin.Core

• Deleted files in OneSignal.Abstraction
• Renamed project and namespace toCom.OneSignal.Abstraction to OneSignalSDK.Xamarin.Core
• Added abstract partial class OneSignalSDKInternal to OneSignalSDK.Xamarin.Core
• Added enums LogType and LogoutOptions in OneSignal.Core
• Added Json and Laters helper classes

OneSignalSDK.Xamarin.Android

• Removed Additional classes from OneSignal.Android
• Added OneSignal Android implementation for OneSignal SDK abstract partial class
• Added Android callback classes that use Later
• Added helper class for conversion of Android native state to Xamarin states.
• Added AndroidX, Firebase messaging, and Kotlin related packages OneSignal.Android

OneSignalSDK.Xamarin.iOS

• Added OneSignal iOS implementation for OneSignal SDK abstract partial class
• Added iOS callback classes that use Later
• Added helper class for conversion of iOS native state to Xamarin states.

OneSignalSDK.Xamarin

• Replaced the IOneSignal interface with OneSignalSDKInternal abstract partial class

Sample Apps

• Updated with new Apis

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This change is 

[tanaynigam]

Reviewed 10 of 10 files at r14, all commit messages. Reviewable status: all files reviewed, 9 unresolved discussions (waiting on @tanaynigam)

_Samples/Com.OneSignal.Sample.iOS/ViewController.cs, line 45 at r14 (raw file):_

      //partial void RegisterForPush(UIButton sender)
      //{
      //   SharedPush.RegisterIOS();

Make sure iOS notification prompting works, if this isn't needed remove to do that remove this commented out code.

Samples/Com.OneSignal.Sample.Shared/SharedPush.cs, line 106 at r14 (raw file):

      // No effect on Android, device auto registers without prompting.
      //public static void RegisterIOS() {
      //   OneSignal.Default.RegisterForPushNotification();

This method is in SharedPush, don't we need to keep it for this to work for iOS?

Replacing it with PromptForPushNotificationsWithUserResponse