[feat] sync webview theme with window theme on Android

[FlysoftBeta]

Describe the problem

I am building an android app using tauri, and there is a white screen on start, it looks like the following:

but actually the webpage supports dark mode, after the webview is loaded, the background turns dark.

Describe the solution you'd like

I would like to make the app theme match with the webpage, not only the background color, but also the action bar's color
.

Alternatives considered

No response

Additional context

A pr with similar functionality, but it's a Windows implementation: #5874

[amrbashir]

you can control the status bar colors and behavior by modifying gen/android/app/src/main/res/values/themes.xml and call the needed kotlin code in gen/android/app/src/main/java/com/tauri/tauri-app/ManiActivity.kt, see https://stackoverflow.com/questions/29311078/android-completely-transparent-status-bar for more info