New review app deployments are hanging

After https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/6665 , new RA deployments are hanging with:

googleapi: Error 400: Invalid value for field 'resource.IPAddress': 'X.X.X.X'. Specified IP address is in-use and would result in a conflict., invalid

@WarheadsSE Says:

Yes, this is something we worked around in our CI for charts/gitlab, using `terraform_up` function, and then looking up `check_domain_ip`

When deploying the `nginx-ingress` chart, one can not re-use `REVIEW_APPS_DOMAIN_IP` by more than one deployment.

cc @ibaum