We use the same condition, which defines against what host some "service"
tasks should run against, several times. It's hard to keep it the same
across the role and ansible spending additional resources to evaluate
it each time, so it's simpler and better for the maintenance to set
a boolean variable which will say for all tasks, that we want to run
only against signle host, if they should run or not now.
Depends-On: https://review.opendev.org/c/openstack/openstack-ansible/+/756310
Change-Id: I41d331fdb5ee95e0c9b9edbb3c7ee19ccd40d98c
a202a34981