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/tasks/calico-policy-controller.yml

@@ -8,6 +8,6 @@
     name: "calico-policy-controller"
     kubectl: "{{bin_dir}}/kubectl"
     filename: "{{kube_config_dir}}/calico-policy-controller.yml"
-    namespace: "{{kube_namespace}}"
+    namespace: "{{system_namespace}}"
     resource: "rs"
   when: inventory_hostname == groups['kube-master'][0]