Check for metadata hash if specified am: abb082f499 am: 4c5cdb44f5 am: 37d56c26a0

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2568976

Change-Id: I7ddc60c8c419c13c2090879661ea81767dd088f4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>