Ensure upgrade step orchestration accross roles.

Ensure upgrade step orchestration accross roles.

Currently we don't enforce step ordering across role, only within
role.  With custom role, we can reach a step5 on one role while the
cluster is still at step3, breaking the contract announced in the
README[1] where each step has a guarantied cluster state.

We have to remove the conditional here as well as jinja has no way to
access this information, but we need jinja to iterate over all enabled
role to create the orchestration.

This deals only with Upgrade tasks, there is another review to deal
with UpgradeBatch tasks.

[1] https://github.com/openstack/tripleo-heat-templates/blob/master/puppet/services/README.rst

Closes-Bug: #1679486

Change-Id: Ibc6b64424cde56419fe82f984d3cc3620f7eb028
(cherry picked from commit d286892c785b8b81a866ea3c6a459d1fc4a347e8)