@Override
    protected void addChild(ClusterControllerContainerCluster cluster) {
        super.addChild(cluster);
        this.containerCluster = cluster;
    }
Used if clustercontroller is run standalone (not as part of the config server ZooKeeper cluster)
to provide common configs to container components.

@author Ulf Lilleengen
config-model/src/main/java/com/yahoo/vespa/model/admin/clustercontroller/ClusterControllerCluster.java