Switch to Fernet token format
Switch to Fernet token format

Configure Keystone's token driver for Fernet[0] instead of UUID. The
latter has been deprecated for some time now, and will be removed as
of the 'Rocky' release of OpenStack[1].

Fernet has been the default since 'Ocata'.

NB: This change is prompted by a bug in Keystone affecting federated users
and their group mapping[2].

 [0] https://docs.openstack.org/keystone/queens/admin/identity-fernet-token-faq.html
 [1] https://review.openstack.org/#/c/543060/
 [2] https://bugs.launchpad.net/keystone/+bug/1758460

SKA-ScienceDataProcessor/alaska-kayobe-config