Add cluster-name to external-openstack-cloud-controller-manager (#7055)

If cluster-name is not set, the default value "kubernetes" is used.
The loadbalancees created by Kubernetes follow the format:
  kube_service_clusterName_serviceNamespace_serviceName
If 2 clusters create a loadbalancer for the same service in the same
namespace, they will share the same non-working loadbalancer.

Signed-off-by: Cedric Hnyda <cedric.hnyda@itera.io>

roles/kubernetes-apps/external_cloud_controller/openstack/templates/external-openstack-cloud-controller-manager-ds.yml.j2

@@ -42,6 +42,7 @@ spec:
             - --v=1
             - --cloud-config=$(CLOUD_CONFIG)
             - --cloud-provider=openstack
+            - --cluster-name={{ cluster_name }}
             - --use-service-account-credentials=true
             - --address=127.0.0.1
 {% for key, value in external_openstack_cloud_controller_extra_args.items() %}