audio policy: force device update if disconnected

Force the new device selection to be applied when a device is disconnected
even if none is select. This is to indicate to the audio HAL that current
device selection is not valid anymore even if no new device is selected because
no audio track is active.

Bug 7141149.

Change-Id: Iade02fb53a4cc2051fce9da07870c5391396b696
1 file changed