Add cinder service user metadata

Enable cinder service user by default

Change-Id: I7bd21385b43cefa8b8a95f9d11f0c007b6cc9f2b
Related-Prod: PROD-25985
diff --git a/cinder/control/single.yml b/cinder/control/single.yml
index b8f670d..2d662f9 100644
--- a/cinder/control/single.yml
+++ b/cinder/control/single.yml
@@ -31,6 +31,8 @@
       identity:
         protocol: ${_param:internal_protocol}
         region: ${_param:openstack_region}
+      service_user:
+        enabled: ${_param:cinder_service_user_enabled}
       barbican:
         enabled: ${_param:barbican_integration_enabled}
       message_queue: