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-networking/api/BUILD b/apps/k8s-networking/api/BUILD
index 1995985..e1e477c 100644
--- a/apps/k8s-networking/api/BUILD
+++ b/apps/k8s-networking/api/BUILD
@@ -6,6 +6,7 @@
     "@logging_interceptor//jar",
     "@jackson_dataformat_yaml//jar",
     "@snakeyaml//jar",
+    "@commons_net//jar",
 ]
 
 TEST_DEPS = TEST_ADAPTERS + [