It captures the information needed for the UI logic related to rendering of the video track (and later images) to the surface.
The video size will be correct only after the Player decoded the video onto the surface and can't be reliably extracted from MediaItem's metadata. The information about the video's true aspect ratio helps inform the UI elements (such as PlayerSurface Composable) how to customize the Modifiers.
Use this state in demo-compose to show off functionality of changing `PlayerSurface`'s aspectRatio
PiperOrigin-RevId: 714104260
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