Skip arbitrary container tests for Ceph

The Ceph backup driver does not support an arbitrary container name
without there being a corresponding pool already configured on the
cluster.  Unlike swift, Ceph cannot create a pool to match a container
name on the fly, and this test is not supported when configured with a
ceph-backed cinder backup service.

This patch fixes commit f62703b5a4 which
causes the ceph job to fail.

Change-Id: Ic8d60d58982bb44bfb233aeccc60c35e8eb0aaf3

tempest/api/volume/test_volumes_backup.py

@@ -50,6 +50,8 @@ class VolumesBackupsTest(base.BaseVolumeTest):
                                                 'available')
         return restored_volume
 
+    @testtools.skipIf(CONF.volume.storage_protocol == 'ceph',
+                      'ceph does not support arbitrary container names')
     @decorators.idempotent_id('a66eb488-8ee1-47d4-8e9f-575a095728c6')
     def test_volume_backup_create_get_detailed_list_restore_delete(self):
         # Create a volume with metadata