Move resize_available class variable into skip decorators

We shouldn't do a getattr on CONF in the class definition. It will cause
import errors if there isn't a config file. Just use
CONF.compute_feature_enabled.resize in the skip decorator.

Change-Id: I6361ceb45b1e2796e00bb94279b5437c8902294d
diff --git a/tempest/api/compute/servers/test_server_actions.py b/tempest/api/compute/servers/test_server_actions.py
index 8e9481f..cc2d1ee 100644
--- a/tempest/api/compute/servers/test_server_actions.py
+++ b/tempest/api/compute/servers/test_server_actions.py
@@ -29,7 +29,6 @@
 
 
 class ServerActionsTestJSON(base.BaseV2ComputeTest):
-    resize_available = CONF.compute_feature_enabled.resize
     run_ssh = CONF.compute.run_ssh
 
     def setUp(self):
@@ -184,7 +183,8 @@
             if current_flavor == self.flavor_ref else self.flavor_ref
         return current_flavor, new_flavor_ref
 
-    @testtools.skipIf(not resize_available, 'Resize not available.')
+    @testtools.skipUnless(CONF.compute_feature_enabled.resize,
+                          'Resize not available.')
     @test.attr(type='smoke')
     def test_resize_server_confirm(self):
         # The server's RAM and disk space should be modified to that of
@@ -203,7 +203,8 @@
         resp, server = self.client.get_server(self.server_id)
         self.assertEqual(new_flavor_ref, server['flavor']['id'])
 
-    @testtools.skipIf(not resize_available, 'Resize not available.')
+    @testtools.skipUnless(CONF.compute_feature_enabled.resize,
+                          'Resize not available.')
     @test.attr(type='gate')
     def test_resize_server_revert(self):
         # The server's RAM and disk space should return to its original
diff --git a/tempest/api/compute/v3/servers/test_server_actions.py b/tempest/api/compute/v3/servers/test_server_actions.py
index 103f47c..c377c30 100644
--- a/tempest/api/compute/v3/servers/test_server_actions.py
+++ b/tempest/api/compute/v3/servers/test_server_actions.py
@@ -26,7 +26,6 @@
 
 
 class ServerActionsV3Test(base.BaseV3ComputeTest):
-    resize_available = CONF.compute_feature_enabled.resize
     run_ssh = CONF.compute.run_ssh
 
     def setUp(self):
@@ -175,7 +174,8 @@
             if current_flavor == self.flavor_ref else self.flavor_ref
         return current_flavor, new_flavor_ref
 
-    @testtools.skipIf(not resize_available, 'Resize not available.')
+    @testtools.skipUnless(CONF.compute_feature_enabled.resize,
+                          'Resize not available.')
     @test.attr(type='smoke')
     def test_resize_server_confirm(self):
         # The server's RAM and disk space should be modified to that of
@@ -194,7 +194,8 @@
         resp, server = self.client.get_server(self.server_id)
         self.assertEqual(new_flavor_ref, server['flavor']['id'])
 
-    @testtools.skipIf(not resize_available, 'Resize not available.')
+    @testtools.skipUnless(CONF.compute_feature_enabled.resize,
+                          'Resize not available.')
     @test.attr(type='gate')
     def test_resize_server_revert(self):
         # The server's RAM and disk space should return to its original