Add RBAC test for updating volume group

This commit adds a test for updating a volume group, providing
coverage for group:update policy action.

Change-Id: Ifc6ccb8d79fa01c3dfe951282e004f79db2d01cd
diff --git a/patrole_tempest_plugin/tests/api/volume/test_groups_rbac.py b/patrole_tempest_plugin/tests/api/volume/test_groups_rbac.py
index 6b07aaa..606b58a 100644
--- a/patrole_tempest_plugin/tests/api/volume/test_groups_rbac.py
+++ b/patrole_tempest_plugin/tests/api/volume/test_groups_rbac.py
@@ -90,6 +90,18 @@
         self.rbac_utils.switch_role(self, toggle_rbac_role=True)
         self.groups_client.list_groups(detail=True)['groups']
 
+    @decorators.idempotent_id('f499fc48-df83-4917-bf8d-783ebf6f080b')
+    @rbac_rule_validation.action(
+        service="cinder",
+        rule="group:update")
+    def test_update_group(self):
+        group = self._create_group(group_type=self.group_type_id,
+                                   volume_types=[self.volume_type_id])
+        updated_name = data_utils.rand_name(self.__class__.__name__ + '-Group')
+
+        self.rbac_utils.switch_role(self, toggle_rbac_role=True)
+        self.groups_client.update_group(group['id'], name=updated_name)
+
     @decorators.idempotent_id('66fda391-5774-42a9-a018-80b34e57ab76')
     @rbac_rule_validation.action(
         service="cinder",
diff --git a/releasenotes/notes/update-group-volume-test-06c7475ccbe36aa8.yaml b/releasenotes/notes/update-group-volume-test-06c7475ccbe36aa8.yaml
new file mode 100644
index 0000000..77cf196
--- /dev/null
+++ b/releasenotes/notes/update-group-volume-test-06c7475ccbe36aa8.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Add test for updating a volume group, providing coverage for group:update
+    policy action.