Relinquish mastership when device reports "permission" denied event

Also reduces default pipeconf watchdog probe interval
Also fixes NPE on GDP when device is unreachable

Change-Id: Ie2fe1874b0883a037596d9a555a2f8cc030a55a6
(cherry picked from commit d797e2c28505fbdbb8597038ebcf977a053bae72)
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 0316ed4..4e0ea60b 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
@@ -42,7 +42,12 @@
         /**
          * Channel Event.
          */
-        CHANNEL_EVENT
+        CHANNEL_EVENT,
+
+        /**
+         * Permission denied (not master).
+         */
+        PERMISSION_DENIED,
     }
 
     public P4RuntimeEvent(Type type, P4RuntimeEventSubject subject) {