This centralizes all user and group creation into a single source. This
will fix any current and furture uid/gid mismatches (such as with
nova-libvirt).
In the process, we also unify users between the distros in a standard
way. The users in the following containers change from thier defaults:
Ubuntu: _chrony user is now chrony
Ubuntu: memcache user is now memcached
All: qemu user is used for ownership and socket permissions
All uid and gid numbers are customizable via kolla-build.conf
Co-Authored-By: Kris Lindgren <klindgren@godaddy.com>
Change-Id: I120f26ab0683dc87d69727c3df8d4707e52a4543
Partially-Implements: blueprint static-uid-gid