Replace 'distribution' with 'ansible_os_family'.
Replace 'distribution' with 'ansible_os_family'.

The change allows to use CentOS base systems as hypervisors.

Change-Id: I0a0e29895e07be80552a445d5adf1edd1c194c56

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared