Fix the way service disabling

The current way only disables service but does not stop it.
Service should be stopped and disabled.

PROD-36897

Change-Id: I5c4f1afecc4439c3a4fc4535beff4ad127a16f5f
diff --git a/nova/controller.sls b/nova/controller.sls
index 7e93392..45d8224 100644
--- a/nova/controller.sls
+++ b/nova/controller.sls
@@ -69,7 +69,8 @@
 
 {%- if not controller.get('serial_proxy',{}).get('enabled', False) %}
 nova_serialproxy_service_disable:
-  service.disabled:
+  service.dead:
+    - enable: false
     - name: nova-serialproxy
     - require:
       - pkg: nova_controller_packages