Opt-in mechanism for RemoteControlClient position anti-drift check

RemoteControlClient has an interface for the framework to query
 the playback position. This mechanism is used to detect
 when the estimated position drifts from the real position by
 having the framework regularly poll (every 15s when playing at
 1x) this interface and compare against the estimation.
But this mechanism:
 - should only be used when IRemoteControlDisplay implementation
  care about position display
 - should not be used by default because the implementation of
  the position query interface might involve network traffic
  in some remote media player implementation for instance.

This CL implements an opt-in mechanism to be used by
 implementators of IRemoteControlDisplay, to request the
 anti-drift mechanism to be turned on.

bug 8120740

Change-Id: I1baa3e515546ac41e0ac9c3a41bfa3147ecf3d7f