Remove TV specific methods from Pip interface

Remove TV "legacy" methods from Pip interface:
  - addListener(...) that takes .tv.PipController.Listener objects
  - getMediaController()
  - getPlaybackState()
Leave both methods in .tv.PipController with package-private access
level.

Bug: 165795012
Bug: 169575409
Test: make WindowManager-Shell
Change-Id: I335d7d098b1a7af2c7958cd234553e7fde6557ac