This is the main patch for the migration of the stable/21.10
charm to charmhub for the stable/train branch (train track on
charmhub). This patch initially supports bionic from queens
to train, and does not support ussuri. It supports upgrades
from bionic-queens to bionic-train (with each intermediate
step needed). Crucially it does NOT set a default
openstack-origin, which means installing train/stable
without specifying the openstack-origin will result in a
bionic-queens installation. This is intentional as the branch
covers queens to train.
func-test-pr: https://github.com/openstack-charmers/zaza-openstack-tests/pull/883
Change-Id: I86177cb20309fd42941df894cc9ee5a18c36c59f
e391f954b3