ONOS-3088 fix - exlude package processing for non-ARP or non-IPV6 packages

Change-Id: I24c942e017f36dd6dd9fca2c37e77cdcb328e21d

@@ -231,6 +231,10 @@ public class ProxyArp {
                 }
             }
 
+            if (ethPkt.getEtherType() != TYPE_ARP && ethPkt.getEtherType() != TYPE_IPV6) {
+                return;
+            }
+
             //handle the arp packet.
             proxyArpService.handlePacket(context);
         }