ignore invlaid play position update from remote control client.

differentiate between applications that use
 the new RemoteControlClient APIs to pass a playback position but
 don't have one yet, and applications that use the legacy API and
 will never pass a position.

bug:9294855
Change-Id: I015b9ded72497464352a9fbb6a605cedfffad373
Merge "ignore invlaid play position update from remote control client." into jb-mr2-dev
Merge tag 'android-4.3.1_r1' into HEAD

Android 4.3.1 Release 1