am 2dc7c6c4: merge from open-source master

Merge commit '2dc7c6c4153380fc64b99d37d763d3f0d1cac04d' into kraken

* commit '2dc7c6c4153380fc64b99d37d763d3f0d1cac04d':
  Add and document .nomedia constant for MediaStore (Issue 6365)