Add test content provider to mock uri mime types

Add a content provider that returns getType and getStreamTypes based on
the URI query parameters. That allows us not to rely on the debug hook
to override URI mime types, mock files with previes, and makes our
integration tests more integral.

Bug: 280237072
Test: tests themselves
Change-Id: I70835439e8b8b41f4dc633f218d662c2bc42c3ae
6 files changed