Prepare disks for Kolla-Ansible CI run.
**Role Variables**
.. zuul:rolevar:: kolla_ansible_setup_disks_filepath
Path to allocated file passed to loopmount
.. zuul:rolevar:: kolla_ansible_setup_disks_lv_name
Logical volume name to create (skipped if not set)
.. zuul:rolevar:: kolla_ansible_setup_disks_vg_name
Volume group name to create