Including nodeId in DefaultPacketRequest so that we do not prematurely withdraw intercepts when a node is shutdown

Change-Id: If6ae0be8f53a4a158af37e6cc4938309a5e9991b
diff --git a/core/api/src/main/java/org/onosproject/net/packet/PacketRequest.java b/core/api/src/main/java/org/onosproject/net/packet/PacketRequest.java
index dc09219..32f7cd5 100644
--- a/core/api/src/main/java/org/onosproject/net/packet/PacketRequest.java
+++ b/core/api/src/main/java/org/onosproject/net/packet/PacketRequest.java
@@ -15,6 +15,7 @@
  */
 package org.onosproject.net.packet;
 
+import org.onosproject.cluster.NodeId;
 import org.onosproject.core.ApplicationId;
 import org.onosproject.net.flow.TrafficSelector;
 
@@ -44,4 +45,10 @@
      */
     ApplicationId appId();
 
+    /**
+     * Obtain the node id.
+     *
+     * @return an node id
+     */
+    NodeId nodeId();
 }