Address standalone kubelet config case

Also place in global vars and do not repeat the kube_*_config_dir
and kube_namespace vars for better code maintainability and UX.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/kubernetes-apps/ansible/templates/calico-policy-controller.yml.j2

@@ -2,7 +2,7 @@ apiVersion: extensions/v1beta1
 kind: ReplicaSet
 metadata:
   name: calico-policy-controller
-  namespace: {{ kube_namespace }}
+  namespace: {{ system_namespace }}
   labels:
     k8s-app: calico-policy
     kubernetes.io/cluster-service: "true"
@@ -15,7 +15,7 @@ spec:
   template:
     metadata:
       name: calico-policy-controller
-      namespace: kube-system
+      namespace: {{system_namespace}}
       labels:
         kubernetes.io/cluster-service: "true"
         k8s-app: calico-policy