Send Media button events as foreground Intent

Send foreground intent for Media Button events to Music Player
so that there is no delay in handling these Intents after the
device is rebooted.

Change-Id: I952a8af93586cb96c0a9f6dc910bfb49287f4b9a
CRs-fixed: 611219
Merge "Send Media button events as foreground Intent" into kk4.4