Fix broken playlist tests. MediaProvider will be creating the DATA path automatically, so the caller shouldn't specify an invalid path. Also fix bug in test media, since "mp3_3" doesn't resolve to a valid MIME type. Bug: 132359020, 143549606 Test: atest --test-mapping packages/providers/MediaProvider Change-Id: If759e8e8742d51dc8ac4b32b4fe5c845a67a8a75