Extend DocumentsContract search to accept mime types

1. Add the key of query arguments and match method
   in DocumentsContract.
2. Implement new querySearchDocuments method in
   DocumentsProvider, ExternalStoragProvider and
   FileSystemProvider.

Bug: 111786939
Test: Manual Test
Change-Id: I04e9f2be971f10ac1e9584a3486c948aaddea0a4