RHEV : Unable to add Openstack Glance as a External Provider.

Issue

• As per the RHEV-M 3.3 release note it is now possible and supported to add glance from Openstack as an external image provider. However when trying to do so, the connectivity test fails with the message

 "Failed to communicate with the external provider" 

• In RHEV 3.5 I can see the following errors in the /var/log/ovirt-engine/engine.log while trying to add the glance provider:

[In engine.log]

2015-03-24 11:23:04,289 INFO  [org.ovirt.engine.core.bll.provider.AddProviderCommand] (ajp-/127.0.0.1:8702-7) [34286370] Running command: AddProviderCommand internal: false. Entities affected :  ID: aaa00000-0000-0000-0000-123456789aaa Type: SystemAction group CREATE_STORAGE_POOL with role type ADMIN
2015-03-24 11:23:04,340 INFO  [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (ajp-/127.0.0.1:8702-7) [34286370] Correlation ID: 
34286370, Call Stack: null, Custom Event ID: -1, Message: Provider OpenStack_Glance was added. (User: xxxx)
2015-03-24 11:23:14,100 INFO  [org.ovirt.engine.core.utils.transaction.TransactionSupport] (ajp-/127.0.0.1:8702-5) transaction rolled back
2015-03-24 11:23:14,100 ERROR [org.ovirt.engine.core.bll.GetImagesListQuery] (ajp-/127.0.0.1:8702-5) Query GetImagesListQuery failed. Exception message is org.xxx.xxx.xxx.UnrecognizedPropertyException: Unrecognized field "audit_ids" (Class com.xxxx.openstack.keystone.model.Token), not marked as ignorable