Update the env usage of docker_container module

env parameter should be dictionary of key,value pairs rather than
"=" due to ansible docs[0], this PS to update it.

[0]: https://docs.ansible.com/ansible/latest/modules/docker_container_module.html#id3

Change-Id: I79d20b101b56b6df7f2a9162868ec98214f183bf

tools/images/kubeadm-aio/assets/opt/playbooks/roles/deploy-kubeadm-master/tasks/helm-deploy.yaml

@@ -34,7 +34,7 @@
         volumes:
           - /etc/kubernetes/admin.conf:/etc/kubernetes/admin.conf:ro
         env:
-          KUBECONFIG=/etc/kubernetes/admin.conf
+          KUBECONFIG: /etc/kubernetes/admin.conf
       register: kubeadm_aio_tiller_container
       ignore_errors: True
     - name: wait for tiller to be ready