ComponentPeer::setAppStyle() will now update the status and navigation
bar foreground colours, with some caveats:
- Status and nav bar backgrounds are now always completely transparent.
- The navigation bar foreground colour can only be changed on Android
API 26 or higher.
- For platforms using gesture controls instead of button controls, the
system automatically determines the colour of the gesture bar. On
those systems, setAppStyle() will only affect the status bar colour.
The goal of this change is to ensure that the safeAreaInsets and
keyboardInsets members of Display correctly take the current system UI
and screen cutouts into account.
This change also enables rendering behind the status bar and navigation
bar for JUCE applications. This is in line with the new defaults in
Android 15, where building against the Android SDK 35 will automatically
enable "edge-to-edge" drawing. Enabling this behaviour on older
platforms too provides a more consistent experience.