`flet build` generates APK with a black icon

Duplicate Check

[X] I have searched the opened issues and there are no duplicates

Describe the bug

Building APK with default settings yields black icon. Related Flutter issue: https://github.com/fluttercommunity/flutter_launcher_icons/issues/600

Code sample

Code

```python import flet as ft def main(page: ft.Page): page.add(ft.SafeArea(ft.Text("Hello, Flet!"))) ft.app(main) ```

To reproduce

[tool.poetry]
name = "my_app"
version = "1.0.0"
description = "My first Flet project"
authors = ["Feodor Fitsner"]

[tool.poetry.dependencies]
python = "^3.8"
flet = "0.25.0.dev3526"

Run the following command to build APK:

flet build apk

Expected behavior

No response

Screenshots / Videos

Captures

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Operating System

macOS

Operating system details

Any version

Flet version

0.25.0

Regression

I'm not sure / I don't know

Suggestions

Set adaptive_icon_background to any non-black color, for example white:

[tool.flet]
android.adaptive_icon_background = "#ffffff"

[tool.poetry]
name = "my_app"
version = "1.0.0"
description = "My first Flet project"
authors = ["Feodor Fitsner"]

[tool.poetry.dependencies]
python = "^3.8"
flet = "0.25.0.dev3526"

Logs

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

Additional details