Pass VolumeProviderCompat.setCurrentVolume() calls to framework

On API21+ devices, calling VolumeProviderCompat.setCurrentVolume()
should call into the underlying framework VolumeProvider's
setCurrentVolume() as well as update its internal mCurrentVolume()
so that subsequent calls to getCurrentVolume() stay in sync.

BUG: 22883066
Change-Id: I6bdbf792a72229cc8ad416fd978abf28e1a9609d
1 file changed