Comment 3 for bug 1959662

The issue looks deeper than that.
There is more of leftovers, like mistral_db_populate.

That means that we would have way more of init-like (one-time) containers to clean up for as well...

Perhaps a better solution would be for FFU to empty that container-startup-config location?
Or maybe make container manager smarter to detect old configs by managed_by instead of the enabled or not status of a service? See https://review.opendev.org/q/I595a998196b6de386a4ff345c39fe1e6a9ed62c6