Add API for CloudMediaProvider to send event updates to PhotoPicker

Add CloudSurfaceEventCallback API through which PhotoPicker receives
playback events from CloudMediaProviders for video preview.

Add API to CloudMediaSurfaceController to set mute/unmute state.

Bug: 195009562
Test: Manual
CTS-Coverage-Bug: 215187981
Change-Id: I50549d2f0200bedb012fe4ac52a7b3fae599d061
Merged-In: I50549d2f0200bedb012fe4ac52a7b3fae599d061
(cherry picked from commit 873a8d0c7652037e9fbfc839750545c2897ba88f)
7 files changed