Adding METADATA to piex and merging with upstream am: f85cc3c7c1 am: fb64679d7c am: 8eef416f69

Original change: https://android-review.googlesource.com/c/platform/external/piex/+/2224358

Change-Id: I53144eb84be0e63afbecca87f48ab367539a1973
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>