Provide a helper Composable for remembering the state instance and launching the listening coroutine that observes the changes in the Player
Add an example to demo-compose of using PlayPauseButtonState inside a PlayPauseButton Composable.
The smart State object has been deemed a preferred solution over collecting Flows due to queuing/timing/buffering limitations. Instead, it uses the new `Player.listen` suspending extension function to catch the relevant events.
PiperOrigin-RevId: 691879975
676a3872a5