CORD-389 Fix for Accton 6712 deployment

Related to this topic:
- Disable the meter collector since right now it is not supported
- Implement extension VLAN ID selector/treatment for OFDPA
    Since it requires two special flow entries to match untagged packets
        0x1ffe/no mask (filtering rule, need to go first)
        0x0000/0x1fff setvid 0x0ffe (assignment rule, need to go second)
- Not able to point /32 IP address to ECMP group. Use /31 instead.

In addition:
- Implement serializer for ExtensionCriterion

Change-Id: I621b3ad14014d7e6945c014cdae4f7cd2939288e
diff --git a/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/ExtensionSelectorInterpreter.java b/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/ExtensionSelectorInterpreter.java
index 7336c3c..5db4386 100644
--- a/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/ExtensionSelectorInterpreter.java
+++ b/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/ExtensionSelectorInterpreter.java
@@ -43,7 +43,7 @@
      *
      * @param factory OpenFlow factory
      * @param extensionSelector extension selector
-     * @return OpenFlow action
+     * @return OpenFlow OXM
      */
     OFOxm<?> mapSelector(OFFactory factory, ExtensionSelector extensionSelector);