Deployers with shared storage systems must ensure that the nova
user and group have consistent UID's and GID's respectively. This
patch adds a configurable option for deployers to set a UID/GID
for the nova user and group. Warnings are provided in the
default/main.yml about the potential dangers of adjusting this
value on a production system
Docs and a release note will be proposed separately in the
OpenStack-Ansible main repository for this change.
Closes-Bug: 1544889
Change-Id: I881555a896455ce3c897d56a143a8a25c088880b