osp13-osp16.1 ffu fails on older environments missing python-docker package

Issue

• During the overcloud upgrade, when you complete the "Upgrading Controller nodes with external Ceph deployments" procedure and run the openstack overcloud upgrade run command with the system_upgrade tags, you might encounter the following error:
  documentation

• The upgrade command which is failing is --> openstack overcloud upgrade run --stack STACK NAME --tags system_upgrade --limit xxxx

2020-11-24 12:55:22,143 p=100846 u=mistral n=ansible | TASK [tripleo-podman : Stop a container] ***************************************
2020-11-24 12:55:22,143 p=100846 u=mistral n=ansible | Tuesday 24 November 2020  12:55:22 -0500 (0:00:00.326)       0:00:32.456 ******
2020-11-24 12:55:22,805 p=100846 u=mistral n=ansible | failed: [xxxx] (item=985976509ce8) => {"ansible_loop_var": "item", "changed": false, "item": "985976509ce8", "msg": "Failed to import the required Python library (Docker SDK for Python: docker (Python >= 2.7) or docker-py (Python 2.6)) on xxxx's Python /usr/bin/python. Please read module documentation and install in the appropriate location. If the required library is installed, but Ansible is using the wrong Python interpreter, please consult the documentation on ansible_python_interpreter, for example via `pip install docker` or `pip install docker-py` (Python 2.6). The error was: No module named docker"}
2020-11-24 12:55:23,159 p=100846 u=mistral n=ansible | failed: [xxxx] (item=06ce45f22ce4) => {"ansible_loop_var": "item", "changed": false, "item": "06ce45f22ce4", "msg": "Failed to import the required Python library (Docker SDK for Python: docker (Python >= 2.7) or docker-py (Python 2.6)) on xxxx 's Python /usr/bin/python. Please read module documentation and install in the appropriate location. If the required library is installed, but Ansible is using the wrong Python interpreter, please consult the documentation on ansible_python_interpreter, for example via `pip install docker` or `pip install docker-py` (Python 2.6). The error was: No module named docker"}