Stop templating kube-system namespace and creating it (#2545)

Kubernetes makes this namespace automatically, so there is
no need for kubespray to manage it.

roles/kubernetes-apps/ansible/templates/kubedns-autoscaler-clusterrole.yml.j2

@@ -17,7 +17,7 @@ kind: ClusterRole
 apiVersion: rbac.authorization.k8s.io/v1beta1
 metadata:
   name: cluster-proportional-autoscaler
-  namespace: {{ system_namespace }}
+  namespace: kube-system
 rules:
   - apiGroups: [""]
     resources: ["nodes"]