Fixed typo in migrations test name.

tests/migrations/test_operations.py

@@ -1380,8 +1380,8 @@ class OperationTests(OperationTestBase):
         self.assertEqual(sorted(definition[2]), ["field", "model_name", "name"])
 
     @skipUnlessDBFeature("supports_stored_generated_columns")
-    def test_add_generate_field(self):
-        app_label = "test_add_generate_field"
+    def test_add_generated_field(self):
+        app_label = "test_add_generated_field"
         project_state = self.apply_operations(
             app_label,
             ProjectState(),