We currently set both actions depending on the playWhenReady state
and we require both actions when converting a platform session to
a Media3 session (if ACTION_PLAY_PAUSE isn't set anyway).
This causes problems in two situations:
- A controller using the platform ACTION_PAUSE/ACTION_PLAY to
determine which button to show in a UI. This needs to be aligned
to the existing Util.shouldShowPlayButton we already use when
setting the PlaybackStateCompat state.
- A session only setting either ACTION_PAUSE or ACTION_PLAY
depending on its state. We should check if the action triggered
by setPlayWhenReady(...) is possible and allow COMMAND_PLAY_PAUSE
accordingly.
PiperOrigin-RevId: 726916720
(cherry picked from commit 28bfb27fb59ceb0cd209ac1eebd803d31f78afa4)
22e5f25648