feat(cinder-csi): allow cluster-id to be pulled from env variables

Signed-off-by: Jack Charlie Munday <1602077@users.noreply.github.com>

Author: 1602077

charts/cinder-csi-plugin/templates/controllerplugin-deployment.yaml

@@ -193,8 +193,10 @@ spec:
               value: unix://csi/csi.sock
             - name: CLOUD_CONFIG
               value: /etc/config/{{ .Values.secret.filename }}
+            {{- if .Values.clusterID }}
             - name: CLUSTER_NAME
               value: "{{ .Values.clusterID }}"
+            {{- end }}
             {{- if .Values.csi.plugin.extraEnv }}
               {{- toYaml .Values.csi.plugin.extraEnv | nindent 12 }}
             {{- end }}