am e3c3dc95: am 9b620cba: am 4e452240: am b8664b37: Merge "According to external test, delete playlists after inserting internal data. It will keep clean environment."

* commit 'e3c3dc95df945b385d550836d0c8c5cf5b17de22':
  According to external test, delete playlists after inserting internal data. It will keep clean environment.