This removes hidden API usages from the fwk to apex, which would be
prohibited.
With this API, the dispatching logic is changed as follows for sending
key events directly to MediaSessionRecord through MediaSessionService.
Before:
PhoneWindow
-> MediaController.dispatch***AsSystemService(key)
-> MediaSessionRecord
After:
PhoneWindow
-> MediaSessionManager.dispatch**AsSystemService(sessionToken, key)
-> MediaSessionService
-> MediaSessionRecord
Bug: 123485698
Test: Build, flash and injected some key events
Change-Id: I3e0bca7565ae2f142c3389322d867700646d5038
8be71c0fe2