Fix android splash

[n13]

Android splash was broken, now fixed

Android doesn't allow bg image so it's just plain dark grey

This can only be tested by starting the app from scratch so it's quite annoying to test

iOS still good

Android now good

[n13]

The PR looks solid. It addresses the Android 12+ splash screen limitations by leveraging the branding feature in flutter_native_splash (v2.4.7+).

Review Summary

1. Dependency Update: Correctly bumped flutter_native_splash to ^2.4.7 in melos.yaml to support the new branding configuration.
2. Configuration:
   • The switch from image to branding in mobile-app/pubspec.yaml is the correct approach for this version of the package to handle splash screens more flexibly across versions.
   • The android_12 specific configuration with an empty icon (android12_icon_empty_1152.png) and a separate branding image (android12_branding_800x320.png) is a standard workaround to replicate a "background image" feel on Android 12+, which otherwise enforces an icon-in-circle design.
3. Assets: New assets for Android 12 branding and the empty icon are included.
4. Native Files: The changes to launch_background.xml (Android) and LaunchScreen.storyboard (iOS) reflect the generated output from the new configuration, adding the branding image views.

Conclusion

The changes are consistent and follow the recommended pattern for handling splash screens on newer Android versions while maintaining support for older ones and iOS.

I've reviewed the code and configuration changes, and they look correct.