Stop using aliases for creds manager

Now that Tempest has stopped using aliases like cls.os
and cls.os_adm [0], Patrole should do the same.

This patch normalizes the usage around os_admin, os_primary and
os_alt.

[0] https://review.openstack.org/#/c/457555/

Change-Id: Ibc826c8c6be2590db9ad9da0831fffeae6d3a01b
Related-Change-Id: I5f7164f7a7ec5d4380ca22885000caa0183a0bf7
39 files changed