If a file {{ node_custom_config }}/magnum/kubeconfig exists, it is
copied to /var/lib/magnum/.kube/config in all Magnum Service Containers.
At this location, the vexxhost/magnum-cluster-api will loo for the Kubeconfig
configuration file to control the Cluster API Control Plane. If the
vexxhost/magnum-cluster-api is installed in the Magnum container images,
control of a cluster API control plane can then take place via the Magnum API.

Depends-On: https://review.opendev.org/c/openstack/kolla/+/902101
Change-Id: I986c5192fe96b9c480a2d8fa87d719a50ce78186