Fix initial aspect ratio

[MGaetan89]

Pull request

Description

This PR fixes various issues related to video size, aspect ratio and media transition:

• The default aspect ratio for video is no longer 1:1, preventing the jump to the actual ratio once the video has started to load
• When transitioning from a video to an audio, the last frame of the video doesn't remain on the screen while the audio is playing
• The surface used to play the media is not created for audio content

Changes made

• Use the current tracks to get the media aspect ratio, instead of the video size
• Set the default aspect ratio in PlayerSurface to 0, meaning that we don't display any surface
  • The integrator can still pass a default aspect ratio to override this
• The surface used to play media is no longer created for audio content

Checklist

• Your branch has been rebased onto the main branch.
• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).
• All pull request status checks pass.

[github-actions]

Code Coverage

Overall Project	53.38% -0.94%	🟢
Files changed	4.83%	🟢

Module	Coverage
:pillarbox-player	69.24% -0.2%	🟢
:pillarbox-ui	0% -2.83%	🟢

Files

Module	File	Coverage
:pillarbox-player	PlayerCallbackFlow.kt	70.72% -0.93%	🟢
:pillarbox-ui	PlayerSurface.kt	0% -21.01%	🟢
	ComposablePlayer.kt	0%	🟢