[ONOS-7902] Add default implementation of k8s node with unit tests

Change-Id: I283967ae14dc7f38e749d7407e4bec698536c18b
diff --git a/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeEvent.java b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeEvent.java
index 841fe01..e9209184 100644
--- a/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeEvent.java
+++ b/apps/k8s-node/api/src/main/java/org/onosproject/k8snode/api/K8sNodeEvent.java
@@ -59,7 +59,7 @@
      * @param type event type
      * @param subject kubernetes node
      */
-    protected K8sNodeEvent(Type type, K8sNode subject) {
+    public K8sNodeEvent(Type type, K8sNode subject) {
         super(type, subject);
     }
 }