This ended up calling into push-to-intermediate-registry with both
docker_images *and* container_images variable set.
This hid from testing that push-to-intermeidate-registry was not
working with only the container_images variable set.
Split these calls up so we don't have both variables defined.
Change-Id: If84b039852f2afc4df66c98e64fcce6f30f51246