Upgrade python/google-api-python-client to v1.8.1 am: cf97e39f87 am: b4903596ac am: 4fd3d4c4ba am: c17cb82fa9 am: c1cd5cc298 am: 2ea37ad81b

Change-Id: I3aa7363796fbf0a384fe3fc795baca85660ce936