Define new type of group CLONE

Used to distinguish between multicast groups and clone sessions in
P4Runtime.

Change-Id: I21a2411c759a1d9524b4a69354c8b343100f8f05
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java b/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java
index 36df2f6..37c0319 100644
--- a/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java
+++ b/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java
@@ -146,6 +146,9 @@
             case "ALL":
                 groupType = Group.Type.ALL;
                 break;
+            case "CLONE":
+                groupType = Group.Type.CLONE;
+                break;
             case "FAILOVER":
                 groupType = Group.Type.FAILOVER;
                 break;