Add overrides parameters for k8s templates.

* Added docker-engine as overrided parameter.
* Added netchecker and helm parameter as a overrided
parameters.

Change-Id: I05de62bd31efe1400533a4ce9f82a59ba13c08fc
diff --git a/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/compute.yml b/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/compute.yml
index 8ac1e8a..a844776 100644
--- a/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/compute.yml
+++ b/classes/cluster/virtual-mcp11-k8s-contrail/kubernetes/compute.yml
@@ -27,7 +27,7 @@
   docker:
     host:
       pkgs:
-        - docker-engine=1.12.6-0~ubuntu-xenial
+        - ${_param:kubernetes_docker_package}
         - python-docker
   kubernetes:
     pool: