Fix RemoteController update in RemoteControlClient registration

A regression was introduced when trying to limit the number of
 internal synchronization generation IDs that caused RCC
 information to be shown only for applications that requested
 audio focus after media button receiver and RCC registration,
 (such as Play Music), not for applications that requested focus
 first (such as Play Movies).
The correct behavior is to always check and update the
 RemoteControllers (seen by MediaFocusControl as RCD interfaces)
 whenever a RemoteControlClient is registered (even if it's a
 re-registration) when it is associated when an entry at the top
 of the remote control stack.

Bug 11657655

Change-Id: I30716e2028f7f718a31e13401b191178735229ff