moved test app param field in scenario inspector

com.unity.perception/Editor/Randomization/Editors/ScenarioBaseEditor.cs

             CreatePropertyFields();
             CheckIfConstantsExist();
 
+            var appParamField = m_Root.Q<ObjectField>("test-app-param");
+            appParamField.objectType = typeof(TextAsset);
+
             var generateConfigButton = m_Root.Q<Button>("generate-json-config");
             generateConfigButton.clicked += () =>
             {
                 PlayerPrefs.SetString(k_ConfigFilePlayerPrefKey, filePath);
             };
 
-            var appParamField = new ObjectField();
-            appParamField.objectType = typeof(TextAsset);
-            appParamField.BindProperty(serializedObject.FindProperty(nameof(ScenarioBase.testAppParam)));
-            var scenarioPropertiesContainer = m_Root.Q<VisualElement>("scenario-properties-container");
-            scenarioPropertiesContainer.Add(appParamField);
-
             return m_Root;
         }
 
                     case "constants":
                         m_HasConstantsField = true;
                         UIElementsEditorUtilities.CreatePropertyFields(iterator.Copy(), m_ConstantsListVisualContainer);
+                        break;
+                    case nameof(ScenarioBase.testAppParam):
                         break;
                     default:
                     {

com.unity.perception/Editor/Randomization/Uxml/ScenarioBaseElement.uxml

             <TextElement
                 class="scenario__info-box"
                 text="Scenarios control the execution flow of your simulation by applying randomization parameters. Make sure to always have only one scenario active within your scene."/>
+            <editor:ObjectField name="test-app-param" label="Test App Param" binding-path="testAppParam"/>
             <VisualElement name="constants-container">
                 <Foldout style="padding-left: 16px" text="Constants" name="constants-list" tooltip="A list of parameters for this scenario that will be JSON serialized in the configuration file."/>
                 <editor:PropertyField name="configuration-file-name" label="Constants File Name" binding-path="serializedConstantsFileName"/>