Defer suspend events on Android when audio is active.

Defer suspend events on Android when audio is active.

Suspend is killing the network connection powering audio
playback for background audio cases. We should not suspend
when there is an active playback going on.

Probably we should also change the HasActiveAudio() logic
on Android to include if there is an active media session --
as otherwise the user will not be able to resume playback
from the media session.

BUG=644515
TEST=background audio continues to work.