Fix: retrieve port bridge port MAC from deviceService rather via ovsdb

1. Derive gateway IP address from POD subnet CIDR.
2. Remove the logic of injecting gateway IP address.

Change-Id: Ice44c1c4b41bc1689954041aee6441a379e5bacd
diff --git a/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNode.java b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNode.java
index 065f2dd..8d6f57c 100644
--- a/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNode.java
+++ b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNode.java
@@ -157,6 +157,27 @@
     PortNumber intgBridgePortNum();
 
     /**
+     * Returns the integration to external patch port number.
+     *
+     * @return patch port number
+     */
+    PortNumber intgToExtPatchPortNum();
+
+    /**
+     * Returns the external to integration patch port number.
+     *
+     * @return patch port number
+     */
+    PortNumber extToIntgPatchPortNum();
+
+    /**
+     * Returns the external bridge to router port number.
+     *
+     * @return port number, null if the port does not exist
+     */
+    PortNumber extBridgePortNum();
+
+    /**
      * Returns the integration bridge's MAC address.
      *
      * @return MAC address; null if the MAC address does not exist
@@ -192,27 +213,6 @@
     MacAddress extGatewayMac();
 
     /**
-     * Returns the integration to external patch port number.
-     *
-     * @return patch port number
-     */
-    PortNumber intgToExtPatchPortNum();
-
-    /**
-     * Returns the external to integration patch port number.
-     *
-     * @return patch port number
-     */
-    PortNumber extToIntgPatchPortNum();
-
-    /**
-     * Returns the external bridge to router port number.
-     *
-     * @return port number, null if the port does not exist
-     */
-    PortNumber extBridgePortNum();
-
-    /**
      * Builder of new node entity.
      */
     interface Builder {