add notification-manager svc endpoint

Created by: wenchajun

Synchronize with kubesphere-config in kubesphere. https://github.com/kubesphere/kubesphere/blob/master/config/ks-core/templates/kubesphere-config.yaml#L27 Expose the endpoint of notification-manager. svc

Signed-off-by: wenchajun dehaocheng@yunify.com