[ONOS-7143] Add arbitration update support by P4RuntimeClient

Change-Id: I671275576018d50447f969166a7b42a28dd93b1d
diff --git a/protocols/p4runtime/api/src/main/java/org/onosproject/p4runtime/api/P4RuntimeEvent.java b/protocols/p4runtime/api/src/main/java/org/onosproject/p4runtime/api/P4RuntimeEvent.java
index 1f04374..ab0146f 100644
--- a/protocols/p4runtime/api/src/main/java/org/onosproject/p4runtime/api/P4RuntimeEvent.java
+++ b/protocols/p4runtime/api/src/main/java/org/onosproject/p4runtime/api/P4RuntimeEvent.java
@@ -33,7 +33,11 @@
          * A packet-in.
          */
         PACKET_IN,
-        // TODO: add mastership, device as soon as we define those.
+
+        /**
+         * Arbitration reply.
+         */
+        ARBITRATION,
     }
 
     public P4RuntimeEvent(Type type, P4RuntimeEventSubject subject) {