Add system/extras/verity/build_verity_metadata.py  to otatools am: e718501021 am: 5d77e7e0c1 am: 9f527d5222 am: b4e6eb0e56
am: 8446284b02

* commit '8446284b02ddab002118842b60c3eca47699345d':
  Add system/extras/verity/build_verity_metadata.py  to otatools

Change-Id: Ie587182a7857a30d54ba1225fbb6d49cdc27f748