AVRCP: Passthrough through MediaSessionService
Send passthrough keys through MediaSessionService instead of trying to
interpret them ourselves, and log who they get dispatched to.
Remove the hack around down fast-forward / rewind.
This should result in a lot less confusion about which app is addressed
when the user is sending a command (such as at car connection time).
Test: play / skip, switch app on phone, reboot, start from carkit, dumpsys logs
Bug:
33828042
Bug:
37476911
Change-Id: I8c8c40cb3792254a3720f64707e67fdcc940edaa
(cherry picked from commit
44a4da788f878d1946301dbf297dd7b938dfd730)