New queryRecentDocs in MediaDocumentsProvider

This implements the new DocumentsProvider#queryRecentDocuments API that
supports flexible limit for max number of recent documents returned.

Bug: 111288304
Test: manual test (patched the DocumentsProvider CL, and test calling
the new API):
1. Test that passing Bundle with QUERY_ARG_LIMIT=5 is honored and
returned is limited to 5.
2. Test that passing null will release the limit to default 64.
3. Test that removing MediaProvider implementation for new method and
implement the old method will automatically redirect the call to old
method (backward compatible with old providers).

Change-Id: Ia42e8aeac62379b35b85af848698eb3ece3f7947
1 file changed