Logging on GKE has incorrect cluster location

[uday-happeo]

Current logging value for resource.labels.location is derived from compute location instead of GKE cluster location. This incorrect value causes us to see no container logs when clicked on "Container Logs" from GKE cluster console UI unless we explicitly remove resource.labels.location filter each time when GKE cluster is regional but logs have location value as zonal.

This is fixed in python logging library: googleapis/python-logging#830 by moving to attribute instance/attributes/cluster-location from metadata server.