The 'kolla-ansible stop' command can be used to stop the services
running on hosts. However, if you run this command in an environment
with heterogeneous nodes (most real world scenarios have at least
control/compute), then it fails. This is because it only checks
whether a container is enabled, and not whether the host is in the
correct group. For example, it fails with nova-libvirt:

    No such container: nova_libvirt to stop.

This change fixes the issue by only attempting to stop containers on
hosts to which they are mapped.

Change-Id: Ibecac60d1417269bbe25a280996ca9de6e6d018f
Closes-Bug: #1868596

Many tasks that use Docker have become specified already, but
not all. This change ensures all tasks that use the following
modules have become:

* kolla_docker
* kolla_ceph_keyring
* kolla_toolbox
* kolla_container_facts

It also adds become for 'command' tasks that use docker CLI.

Change-Id: I4a5ebcedaccb9261dbc958ec67e8077d7980e496

With this change, an operator may be able to stop a
service container without stopping all services in a host.
This change is the starting point to start
fast-forward upgrades support.
In next changes new flags will be introducced to disable
stop dataplane services during upgrades.

Change-Id: Ifde7a39d7d8596ef0d7405ecf1ac1d49a459d9ef
Implements: blueprint support-stop-containers