Merge "fiemap: support FIEMAP_EXTENT_MERGED" am: 286e5aba63 am: 33a4442b54

Original change: https://android-review.googlesource.com/c/platform/system/core/+/1590474

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I444d96fc0143273a2db60b2926ba333459e835c0