Bug 5300223 RemoteControlClient uses PendingIntent

API change so RemoteControlClient is given a PendingIntent in
 its constructor, which will be used for receiving media button
 events from remote controls.
Leave the old constructors (but hidden) to not break
 current functionality until the AudioManager and AudioService
 implementations have been updated.

Change-Id: Ifa12c8036c948931adc386a827dce2936788e1cd