All CNIs: support ANY toleration. (#3391)

Before, Nodes tainted with NoExecute policy did not have calico/weave Pod.
Network pod should run on all nodes whatever happens on a specific node.

Also always set the Pods to be critical.
Also remove deprecated scheduler.alpha.kubernetes.io/tolerations annotations.

roles/network_plugin/contiv/templates/contiv-etcd.yml.j2

@@ -25,8 +25,10 @@ spec:
       nodeSelector:
         node-role.kubernetes.io/master: "true"
       tolerations:
-        - key: node-role.kubernetes.io/master
-          effect: NoSchedule
+        - operator: Exists
+        # Mark pod as critical for rescheduling (Will have no effect starting with kubernetes 1.12)
+        - key: CriticalAddonsOnly
+          operator: "Exists"
       initContainers:
         - name: contiv-etcd-init
           image: {{ contiv_etcd_init_image_repo }}:{{ contiv_etcd_init_image_tag }}