Cluster support for ovn-central. (#9596)

Without minimal cluster configuration, even on a one node control plane,
the health check of the ovn-cental container always fails as it queries the
cluster/status.

roles/network_plugin/kube-ovn/templates/cni-ovn.yml.j2

@@ -249,6 +249,8 @@ spec:
               valueFrom:
                 fieldRef:
                   fieldPath: status.podIP
+            - name: NODE_IPS
+              value: "{{ kube_ovn_central_ips }}"
             - name: POD_NAME
               valueFrom:
                 fieldRef:
@@ -386,6 +388,8 @@ spec:
               valueFrom:
                 fieldRef:
                   fieldPath: spec.nodeName
+            - name: OVN_DB_IPS
+              value: "{{ kube_ovn_central_ips }}"
           volumeMounts:
             - mountPath: /var/run/netns
               name: host-ns