Fix: double check resource existence at receiving addition event

Change-Id: I80fb2b30201e3e770eb5384ecee2b78b32502936
diff --git a/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/impl/K8sEndpointsWatcher.java b/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/impl/K8sEndpointsWatcher.java
index c3139c1..62c15e6 100644
--- a/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/impl/K8sEndpointsWatcher.java
+++ b/apps/k8s-networking/app/src/main/java/org/onosproject/k8snetworking/impl/K8sEndpointsWatcher.java
@@ -170,7 +170,10 @@
             log.trace("Process endpoints {} creating event from API server.",
                     endpoints.getMetadata().getName());
 
-            k8sEndpointsAdminService.createEndpoints(endpoints);
+            if (k8sEndpointsAdminService.endpoints(
+                    endpoints.getMetadata().getUid()) == null) {
+                k8sEndpointsAdminService.createEndpoints(endpoints);
+            }
         }
 
         private void processModification(Endpoints endpoints) {