consolidate the 'set_fact' statements into a single role

[miabbott]

We have a number of set_fact statements littered in the roles directory:

[~/workspaces/projectatomic/atomic-host-tests (master)*]$ git grep set_fact roles/ | wc -l
31

I'd like to get these consolidated into a single role, in order to eliminate any hunting around for where the fact is set or should be set.

[miabbott]

(3) [a-h-t] Consolidate the 'set_fact' statements into a single role