Fixed to not to create gateway group if it is already exists

Also changed some names shorter.

Change-Id: Iaa8aa5ac378fc168e79c9e238090ca817af42261
diff --git a/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackIcmpHandler.java b/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackIcmpHandler.java
index 6eaddf1..7db84bb 100644
--- a/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackIcmpHandler.java
+++ b/apps/openstacknetworking/routing/src/main/java/org/onosproject/openstacknetworking/routing/OpenstackIcmpHandler.java
@@ -331,7 +331,7 @@
     private Map<DeviceId, PortNumber> getExternalInfo() {
         Map<DeviceId, PortNumber> externalInfoMap = Maps.newHashMap();
         gatewayService.getGatewayDeviceIds().forEach(deviceId ->
-                externalInfoMap.putIfAbsent(deviceId, gatewayService.getGatewayExternalPort(deviceId)));
+                externalInfoMap.putIfAbsent(deviceId, gatewayService.getUplinkPort(deviceId)));
         return externalInfoMap;
     }
 }