When the UseMaterial3 MSBuild property is enabled, the ActivityIndicator control should conform to the Material 3 visual design system. However, the current implementation does not fully align with Material 3 behavior.
The ActivityIndicator should apply Material 3–specific styling, including correct indicator colors, proper handling of the IsRunning state, and updated state behaviors. It should also rely on the appropriate Material 3 theme resources to ensure visual consistency across the application.