Add skip for tests test_signed_image_upload_*

Skip tests if barbican_intagration_enabled = False

Related-PROD: PRODX-5292
Change-Id: Ie4fcfc00b0152755e2c82dfd13c6b7e473242871
(cherry picked from commit 09d0f6ff10a83f44b9b999582a94a513ebbb89e8)
(cherry picked from commit bc4e1475c1bc0fd49149aae462afbadc955e895c)
(cherry picked from commit bf331747566c14e0a7b6170e8501500d439b7296)
(cherry picked from commit 698750c31d25c3a7fe7b15f96490ac7f4992f7b8)
(cherry picked from commit 3ab3da8b4a830ee7ca5137bf85856dc79d59c695)
(cherry picked from commit 7495302df73a0d232641d21932ac30a700b9d154)
diff --git a/barbican_tempest_plugin/tests/scenario/test_image_signing.py b/barbican_tempest_plugin/tests/scenario/test_image_signing.py
index 19d2a1f..c05cabb 100644
--- a/barbican_tempest_plugin/tests/scenario/test_image_signing.py
+++ b/barbican_tempest_plugin/tests/scenario/test_image_signing.py
@@ -11,9 +11,10 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
-import testtools
 
 from oslo_log import log as logging
+import testtools
+
 from tempest.api.compute import base as compute_base
 from tempest.common import utils
 from tempest import config
@@ -40,6 +41,9 @@
 
     @decorators.idempotent_id('4343df3c-5553-40ea-8705-0cce73b297a9')
     @utils.services('compute', 'image')
+    @testtools.skipUnless(
+        CONF.compute_feature_enabled.barbican_integration_enabled,
+        'Barbican integration must be enabled.')
     def test_signed_image_upload_and_boot(self):
         """Test that Nova boots a signed image.
 
@@ -64,6 +68,9 @@
     @utils.services('compute', 'image')
     @testtools.skipUnless(CONF.image_signature_verification.enforced,
                           "Image signature verification is not enforced")
+    @testtools.skipUnless(
+        CONF.compute_feature_enabled.barbican_integration_enabled,
+        'Barbican integration must be enabled.')
     def test_signed_image_upload_boot_failure(self):
         """Test that Nova refuses to boot an incorrectly signed image.