am 4c00f637: 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 '4c00f637ad823cf24cc376aac4ca7fec9a745042':
  According to external test, delete playlists after inserting internal data. It will keep clean environment.