[automerger] DO NOT MERGE Rework thumbnail cleanup am: b514ce9b38 am: b8dad6c644 am: 019eec3923 skipped: 9d13b0f6ca am: 4ef2cbc58d am: 31ee079d5f

Change-Id: I3a801f0e6cadeb98e28d91c52062e6e63164bca2