This updates the default OIDCRedirectURI according to the change made
in the example file in keystone repo[1].
[1] https://review.opendev.org/925553
Conflicts:
spec/classes/keystone_federation_openidc_spec.rb
Closes-Bug: #2075349
Change-Id: Ia0f3cbb842a4c01e6a3ca44ca66dc9a8a731720c
(cherry picked from commit fdf2a2b31a)