Revamp support for keyevent handling.

Now any RowPresenter.ViewHolder can handle keyevents.
Fixes playback controls issues when ff/rw are triggered via keyevent.
Also add support for KEYCODE_MEDIA_PLAY and KEYCODE_MEDIA_PAUSE.

b/18933835

Change-Id: I6e4c568524dda538ea7082c8097b481a2e59dff0
12 files changed