APIs for reviewing, listing volumes, hashes.

As part of creating a "default gallery" app in Q, we need to define
the expected contract of how recently captured media can be reviewed
by the user.  Mirrored off the existing CAPTURE intents.

The Q storage work will start calculating SHA-1 hashes for each
media item to identify them in a stable way.

API to list all available volume names on the device, which includes
all attached shared storage devices, like SD cards.

Clean up all Uri creation to use Uri.Builder to ensure that incoming
volumeName values are escaped correctly.

Bug: 111268862
Test: atest cts/tests/tests/provider/src/android/provider/cts/MediaStore*
Change-Id: I460593466d85ff052fd157d8fd784e7ac5b25d78