With the addition of K2K-specific tests in the tempest plugin and a
config toggle in the plugin to disable use of the external IdP, we can
safely add a voting federation job. This also fixes the devstack plugin
to install the xmlsec1 tool which is needed for K2K.
Change-Id: I9dc634e073657ff337751ec67363a57bd10e20d4
Depends-on: https://review.opendev.org/689222
(cherry picked from commit fb0be8e599)
(cherry picked from commit ac74320876)
8f537ed542