Update v3 identity domain configuration tests to work w/ pre-prov

I don't see any limitations by using pre-provisioned
credentials for these tests:

* test_show_default_group_config_and_options
* test_create_domain_config_and_show_config_groups_and_options
* test_create_update_and_delete_domain_config
* test_create_update_and_delete_domain_config_groups_and_opts

Change-Id: I8da97d5998fa50ffce305670cfbac6af74472690
1 file changed