am a98d3c4d: Merge "Add cover image to MediaSet." into ics-mr1

* commit 'a98d3c4dbed84296496f5f710bd1289d735581d5':
  Add cover image to MediaSet.
tree: 8d93306b4106d7704993e9a52487430abc5bf0df
  1. gallerycommon/
  2. src/
  3. src_pd/
  4. tests/