Remove METADATA file am: e6d0d93f27

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3398739

Change-Id: Ib123ac71f4c8c02897c507e297f856c5d6c373cf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>