MAAS incorrectly identifies controller hardware after container move

When you install maas-region in an lxd container on a host, an entry is added to the maasserver_node table for the maas region controller with the hardware_uuid of the host. If you migrate the container to another physical host, then try to enlist the original host's hardware in MAAS, the host will be recognized as the region controller and fail to enlist. A workaround for this is to edit the hardware_uuid of the region controller entry in the maasserver_node table. This is a small edge case but I'm documenting the workaround here so hopefully, others can find it.