Add 3-hours ttl policy for metering.sample queue

Change-Id: Ie067aa6afec58c61f4ce421082d8db401cb675d3
diff --git a/rabbitmq/server/vhost/openstack.yml b/rabbitmq/server/vhost/openstack.yml
index 962bc0a..4320919 100644
--- a/rabbitmq/server/vhost/openstack.yml
+++ b/rabbitmq/server/vhost/openstack.yml
@@ -1,4 +1,7 @@
 parameters:
+  _param:
+    # Ceilometer samples are persisted up to 3 hours by default
+    rabbitmq_ceilometer_ttl: 10800000
   rabbitmq:
     server:
       host:
@@ -15,6 +18,10 @@
           user: openstack
           password: ${_param:rabbitmq_openstack_password}
           policies:
+          - name: Ceilometer
+            pattern: '^metering.sample$'
+            definition: '{"ha-mode": "all", "message-ttl": ${_param:rabbitmq_ceilometer_ttl}}'
+            priority: 10
           - name: HA
             pattern: '^(?!amq\.).*'
             definition: '{"ha-mode": "all", "message-ttl": 120000}'