feat: When attempting to create and objetc must be unique and alrready exists, dont return error return existing object

ref: #855

app/devops/tests/functional/additional_softwareenablefeatureflag_permissions_api.py

@@ -1,10 +1,41 @@
 import pytest
 
+from django.test import Client
+
 
 
 class AdditionalTestCases:
 
 
+    def test_permission_add(self, model_instance, api_request_permissions,
+        model_kwargs, kwargs_api_create
+    ):
+        """ Check correct permission for add 
+
+        Attempt to add as user with permission
+        """
+
+        client = Client()
+
+        client.force_login( api_request_permissions['user']['add'] )
+
+        the_model = model_instance( kwargs_create = model_kwargs )
+
+        url = the_model.get_url( many = True )
+
+        response = client.post(
+            path = url,
+            data = kwargs_api_create,
+            content_type = 'application/json'
+        )
+
+
+        if response.status_code == 405:
+            pytest.xfail( reason = 'ViewSet does not have this request method.' )
+
+        assert response.status_code == 200, response.content
+
+
     def test_returned_data_from_user_and_global_organizations_only(
         self
     ):