Register Versioned with Kryo to fix ONOS-2169

Change-Id: I964f83161a26749953a7c7ae4bf765c01a5a67a6
diff --git a/core/api/src/main/java/org/onosproject/store/service/Serializer.java b/core/api/src/main/java/org/onosproject/store/service/Serializer.java
index 0b00a68..a3e2b0c 100644
--- a/core/api/src/main/java/org/onosproject/store/service/Serializer.java
+++ b/core/api/src/main/java/org/onosproject/store/service/Serializer.java
@@ -57,7 +57,7 @@
         KryoNamespace.Builder builder = new KryoNamespace.Builder();
         namespaces.forEach(builder::register);
         Lists.newArrayList(classes).forEach(builder::register);
-        builder.register(MapEvent.class, MapEvent.Type.class);
+        builder.register(MapEvent.class, MapEvent.Type.class, Versioned.class);
         KryoNamespace namespace = builder.build();
         return new Serializer() {
             @Override