Add df plugin and make description consistent

Change-Id: I06126f5ff6cada3c8d91fbb27bd58998c05ba4c5

deployment/metrics/collectd-container-puppet.yaml

@@ -77,6 +77,7 @@ parameters:
   CollectdDefaultPlugins:
     default:
       - cpu
+      - df
       - disk
       - interface
       - load

environments/metrics/collectd-standalone.yaml

@@ -10,6 +10,8 @@ resource_registry:
 ## These are the default plugins used by collectd
 #
 #   CollectdDefaultPlugins:
+#     - cpu
+#     - df
 #     - disk
 #     - interface
 #     - load
@@ -21,8 +23,8 @@ resource_registry:
 ## All the plugins availables are:
 #
 #   CollectdExtraPlugins:
-#     - disk
-#     - df
+#     - amqp1
+#     - ovs-stats
 #
 ## To choose write plugin use below parameter:
 #