Enable test_secret_stores tests

This patch enables test_secret_stores tests in the SRBAC job. The tests
were previously fixed in this patch [1].

This change builds on the fix. It modifies the configuration of
the SRBAC job so that it is deployed with enabled multiple secret
stores.

[1] https://review.opendev.org/c/openstack/barbican-tempest-plugin/+/883482

Change-Id: I60305a35528fd16ac4e995d11d6d0999a6440e44
2 files changed