Separate per-service host configuration tasks

Currently there are a few services that perform host configuration
tasks. This is done in config.yml. This means that these changes are
performed during 'kolla-ansible genconfig', when we might expect not to
be making any changes to the remote system.

This change separates out these host configuration tasks into a
config-host.yml file, which is included directly from deploy.yml.

One change in behaviour is that this prevents these tasks from running
during an upgrade or genconfig. This is probably what we want, but we
should be careful when any of these host configuration tasks are
changed, to ensure they are applied during an upgrade if necessary.

Change-Id: I001defc75d1f1e6caa9b1e11246abc6ce17c775b
Closes-Bug: #1860161