Fix: add JSON consume type to support postOnBoardNode K8S REST API

Change-Id: Ic6992228f92bb8867749237fa7aa9115840c5398
diff --git a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebResource.java b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebResource.java
index 1786f4c..2f12f25 100644
--- a/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebResource.java
+++ b/apps/k8s-node/app/src/main/java/org/onosproject/k8snode/web/K8sNodeWebResource.java
@@ -258,6 +258,7 @@
      * if the JSON is malformed, and 304 NOT_MODIFIED without the updated config
      */
     @PUT
+    @Consumes(MediaType.APPLICATION_JSON)
     @Produces(MediaType.APPLICATION_JSON)
     @Path("update/postonboard/{hostname}")
     public Response postOnBoardNode(@PathParam("hostname") String hostname) {