Add group rule service, purge flood rules, use group to handle ARP

Change-Id: If0db889d6ab28a4d36f433f16bf84241d2726045
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/util/OpenstackNetworkingUtil.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/util/OpenstackNetworkingUtil.java
index 40d07f5..8837a65 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/util/OpenstackNetworkingUtil.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/util/OpenstackNetworkingUtil.java
@@ -56,6 +56,8 @@
 import org.onosproject.net.device.DeviceService;
 import org.onosproject.net.flow.DefaultTrafficTreatment;
 import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.group.DefaultGroupKey;
+import org.onosproject.net.group.GroupKey;
 import org.onosproject.net.packet.DefaultOutboundPacket;
 import org.onosproject.net.packet.PacketService;
 import org.onosproject.openstacknetworking.api.Constants.VnicType;
@@ -1321,6 +1323,16 @@
     }
 
     /**
+     * Obtains flow group key from the given id.
+     *
+     * @param groupId flow group identifier
+     * @return flow group key
+     */
+    public static GroupKey getGroupKey(int groupId) {
+        return new DefaultGroupKey((Integer.toString(groupId)).getBytes());
+    }
+
+    /**
      * Builds up and a complete endpoint URL from gateway node.
      *
      * @param node gateway node