With Ansible 2.18 ANSIBLE_GATHER_SUBSET env var and corresponding
`gather_subset` config parameter was removed in favor of
`module_defaults` parameter.
We adopt our playbooks to respect previous minimal defaults for
facts gathering, along with intorducing new
ansible variable to control it.
Without these changes all facts are being gathered by default.
Change-Id: I3377b5f623fc8ca195d91ef9f9a3af43e010a99c
Signed-off-by: Dmitriy Rabotyagov <dmitriy.rabotyagov@cleura.com>