Adding tls support ceilometer agent for libvirt

The patch adds TLS support in ceilometer agent in case of
it is enabled for nova compute process.

Change-Id: I86b241bfe59f284c23b3118894e04be6bd6ceede
Related-PROD: PROD-23583
diff --git a/ceilometer/agent/single.yml b/ceilometer/agent/single.yml
index 3803d12..dc75fc5 100644
--- a/ceilometer/agent/single.yml
+++ b/ceilometer/agent/single.yml
@@ -6,8 +6,12 @@
     openstack_rabbitmq_port: 5672
     openstack_rabbitmq_x509_enabled: False
     rabbitmq_ssl_enabled: False
+    ceilometer_agent_ssl_enabled: False
   ceilometer:
     agent:
+      libvirt:
+        ssl:
+          enabled: ${_param:ceilometer_agent_ssl_enabled}
       identity:
         protocol: ${_param:internal_protocol}
       message_queue: