Adding pod priority for all the components. (#3361)

* Changes to assign pod priority to kube components.

* Removed the boolean flag pod_priority_assignment

* Created new priorityclass k8s-cluster-critical

* Created new priorityclass k8s-cluster-critical

* Fixed the trailing spaces

* Fixed the trailing spaces

* Added kube version check while creating Priority Class k8s-cluster-critical

* Moved k8s-cluster-critical.yml

* Moved k8s-cluster-critical.yml to kube_config_dir

roles/kubernetes-apps/ansible/templates/dashboard.yml.j2

@@ -140,6 +140,9 @@ spec:
       labels:
         k8s-app: kubernetes-dashboard
     spec:
+{% if kube_version|version_compare('v1.11.1', '>=') %}
+      priorityClassName: system-cluster-critical
+{% endif %}
       containers:
       - name: kubernetes-dashboard
         image: {{ dashboard_image_repo }}:{{ dashboard_image_tag }}