Regularly, we experience issues in Kolla Ansible deployments because we
use wrong options in OpenStack configuration files. This is because
OpenStack services ignore unknown options. We also need to keep on top
of deprecated options that may be removed in the future. Integrating
oslo-config-validator into Kolla Ansible will greatly help.
Adds a shared role to run oslo-config-validator on each service. Takes
into account that services have multiple containers, and these may also
use multiple config files. Service roles are extended to use this shared
role. Executed with the new command ``kolla-ansible validate-config``.
Change-Id: Ic10b410fc115646d96d2ce39d9618e7c46cb3fbc
6c2aace8d6