Second part of patchset:
https://review.opendev.org/c/openstack/kolla-ansible/+/799229/


in which was suggested to split patch into smaller ones.

THis change adds container_engine to module parameters
so when we introduce podman, kolla_toolbox can be used
for both engines.

Signed-off-by: Ivan Halomi <i.halomi@partner.samsung.com>
Co-authored-by: Martin Hiner <m.hiner@partner.samsung.com>
Change-Id: Ic2093aa9341a0cb36df8f340cf290d62437504ad