Deployment Fails with Property ContainerOvnControllerImage not assigned

Issue

• We are getting a similar error as this article but we can't seem to find any documentation on the below format:

parameter_defaults:
  ContainerImagePrepare:
  - push_destination: 10.10.10.10:8787
    excludes:
      - grafana
    set:
      ceph_alertmanager_image: alertmanager
      ceph_alertmanager_namespace: docker.io/prom
      ceph_alertmanager_tag: v0.16.2
      ceph_image: rhceph-4-rhel8
      ceph_namespace: registry.redhat.io/rhceph-beta
      ceph_node_exporter_image: node-exporter
      ceph_node_exporter_namespace: docker.io/prom
      ceph_node_exporter_tag: v0.17.0
      ceph_prometheus_image: prometheus
      ceph_prometheus_namespace: docker.io/prom
      ceph_prometheus_tag: v2.7.2
      ceph_tag: latest
      name_prefix: openstack-
      name_suffix: ''
      namespace: registry.redhat.io/rhosp-beta
      neutron_driver: ovn
      rhel_containers: false
      tag: 16.0
    tag_from_label: '{version}-{release}'
  ContainerImageRegistryCredentials:
    registry.redhat.io:
        username: password

• Overcloud deployment fails with:

2020-01-20 22:19:50Z [overcloud.CephStorageServiceChain]: CREATE_COMPLETE  state changed

 Stack overcloud/6108319c-d718-4802-88e0-d2d0ddc053fe CREATE_FAILED

overcloud.ControllerServiceChain.ServiceChain:
  resource_type: OS::Heat::ResourceChain
  physical_resource_id:
  status: CREATE_FAILED
  status_reason: |
    resources.ServiceChain: Property error: resources[121].properties: Property ContainerOvnControllerImage not assigned
overcloud.ComputeServiceChain.ServiceChain:
  resource_type: OS::Heat::ResourceChain
  physical_resource_id:
  status: CREATE_FAILED
  status_reason: |
    resources.ServiceChain: Property error: resources[45].properties: Property ContainerOvnControllerImage not assigned
Heat Stack create failed.
Heat Stack create failed.