SDK / exoplayer

*** Original commit ***

Make audio track min buffer size configurable.

Move the code in its own class as DefaultAudioTrack
is getting very big. It also help for testability.

The new class is easily configurable and highly tested.
Manual test was used to catch any regression.

https://github.com/google/ExoPlayer/issues/8891

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PiperOrigin-RevId: 415469179