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/network_plugin/contiv/templates/contiv-netplugin.yml.j2

@@ -22,6 +22,9 @@ spec:
       annotations:
         scheduler.alpha.kubernetes.io/critical-pod: ''
     spec:
+{% if kube_version|version_compare('v1.11.1', '>=') %}
+      priorityClassName: system-node-critical
+{% endif %}
       hostNetwork: true
       hostPID: true
       tolerations: