Change scenario test 'test_resize_server_confirm'

test_server_advanced_ops.test_resize_server_confirm is a duplicate
of test_server_actions.test_resize_server_confirm, so rather than
delete it for being redundant, let's enhance it to be different.

There are currently no resize/migrate tests in Tempest which
resize a volume-backed instance, so this changes the scenario
test to use a volume-backed instance for the resize.

This change is pretty simple, but anyone that was blacklisting
the test based on the name would be broken. However, they should
be blacklisting on the test uuid anyway, so meh.

Related to nova blueprint libvirt-instance-storage

Change-Id: Ie91b2881cb59638ac6e533ab93024dbc42111772
diff --git a/tempest/scenario/test_server_advanced_ops.py b/tempest/scenario/test_server_advanced_ops.py
index 4b932ce..504d72b 100644
--- a/tempest/scenario/test_server_advanced_ops.py
+++ b/tempest/scenario/test_server_advanced_ops.py
@@ -31,7 +31,7 @@
     """The test suite for server advanced operations
 
     This test case stresses some advanced server instance operations:
-     * Resizing an instance
+     * Resizing a volume-backed instance
      * Sequence suspend resume
     """
 
@@ -50,10 +50,10 @@
     @test.idempotent_id('e6c28180-7454-4b59-b188-0257af08a63b')
     @testtools.skipUnless(CONF.compute_feature_enabled.resize,
                           'Resize is not available.')
-    @test.services('compute')
-    def test_resize_server_confirm(self):
+    @test.services('compute', 'volume')
+    def test_resize_volume_backed_server_confirm(self):
         # We create an instance for use in this test
-        instance = self.create_server(wait_until='ACTIVE')
+        instance = self.create_server(wait_until='ACTIVE', volume_backed=True)
         instance_id = instance['id']
         resize_flavor = CONF.compute.flavor_ref_alt
         LOG.debug("Resizing instance %s from flavor %s to flavor %s",