Reconcile MediaStore with MediaMetadataRetriever.

Over the last year we've been converging on saying that MediaProvider
is an indexed view of values that developers can obtain directly from
MediaMetadataRetriever.  This change starts indexing several fields
of interest to bring these two surfaces into sync.

Since we're going to be asking MediaMetadataRetriever about audio,
video, and image files, it could return any metadata values for any
of those file types, so we're adding and promoting fields up to the
MediaColumns level.

Bring back APIs related to "trashing" media items; they had been in
place for the last release, but were hidden until we had firm
requests to add them, and partners have now requested them.  Also
add APIs for marking media items as "favorite", as requested by
partners.

Bug: 135343128, 142478744, 122025511, 142498573
Test: atest --test-mapping packages/providers/MediaProvider
Change-Id: Ie839ec1b2eed621786d0d10f35a061cbc52f192b