Now property initializing enum field with default value

com.unity.perception/Editor/Randomization/ParameterElement.cs

             ToggleTargetContainer();
 
             var frequencyField = this.Q<EnumField>("application-frequency");
+            frequencyField.Init(ParameterApplicationFrequency.OnIterationSetup);
             m_ApplicationFrequency = m_Target.FindPropertyRelative("applicationFrequency");
             frequencyField.BindProperty(m_ApplicationFrequency);
 

com.unity.perception/Runtime/Randomization/Parameters/ParameterTarget.cs

     {
         [SerializeField] internal GameObject gameObject;
         [SerializeField] internal Component component;
-        [SerializeField] internal string propertyName = "";
+        [SerializeField] internal string propertyName = string.Empty;
         [SerializeField] internal FieldOrProperty fieldOrProperty = FieldOrProperty.Field;
         [SerializeField] internal ParameterApplicationFrequency applicationFrequency = ParameterApplicationFrequency.OnIterationSetup;