After switching from Heat workflow resources to external_deploy_tasks,
the `ceph-upgrade run` command no longer works and can be
dropped. Instead we'll be using `external-update run` and
`external-upgrade run` commands, which will not do stack update. It
will run Ansible and for Ceph specifically it will set the necessary
playbook directly via Ansible.
Partial-Bug: #1783949
Change-Id: I3490163bc426d070e245387201d64e07b908c74f
Depends-On: I228ce6228d0bd0bd4d40bc7a7cdd6bfe98a7a6ed
b82f743ab1