CDD: Require double-tap play/pause to be mapped to next track.

- Device implemenations MUST make sure
MediaSession.Callback#onMediaButtonEvent considers double tap of
KEYCODE_HEADSETHOOK or KEYCODE_MEDIA_PLAY_PAUSE as KEYCODE_MEDIA_NEXT.
- This way, apps in foreground and using mediasession API's can
switch to next track on a double-tap of play/pause.

Bug: 63125399
Test: Run make_cdd.py
Change-Id: I154fe3ff97737aca153f4c7735fe1a91f9fbe4a3
2 files changed