Consistently access facts via the ansible_facts.* namespace

[Normo]

Currently, the role failed to run with INJECT_FACTS_AS_VARS set to False as the required ansible_* variables are not defined.

The configuration variable INJECT_FACTS_AS_VARS and the Ansible fact namespace ansible_facts.* have been added in Ansible 2.5. In the porting guide of that version, it stated that:

A new configuration variable, inject_facts_as_vars, has been added to ansible.cfg. Its default setting, 'True', keeps the 2.4 behavior of facts variables being set in the old ansible_* locations (while also writing them to the new namespace). This variable is expected to be set to 'False' in a future release. When inject_facts_as_vars is set to False, you must refer to ansible_facts through the new ansible_facts.* namespace.