tests: fix the size on the second data LV

tests: fix the size on the second data LV

The commit replaces the pv/vg/lv commands used with the ansible command
module by the lvg and lvol modules.
This also fixes the size of the second data LV because we were only using
50% of the remaining space instead of 100%.

With a 50G device, the result was:
  - data-lv1 was 25G
  - data-lv2 was 12.5G
Instead of:
  - data-lv1 was 25G
  - data-lv2 was 25G

Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>