SDK / exoplayer

This makes the delegation model more explicit, and prevents the javadoc
compiler from just pulling in the Player javadoc automatically - which
can lead to some confusion when some method definitions in Player depend
on other methods (e.g. seekForward() is defined in terms of
getSeekForwardIncrement()).

Issue: google/ExoPlayer#9897

#minor-release

PiperOrigin-RevId: 426359004