Fsync directory contents am: bcc64c495a am: 9f3ee1d87a

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3056642

Change-Id: I1b7339a292a85d7bba41ee2ac3d148e9ba8449ec
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>