No Embedded Instance for C++ Components that subclass BoxComponent

4.23/4.24

Embedded instance is never created for subclasses of `BoxComponent`. I noticed that the UE4 editor doesn't even let you create a blueprint subclass of these items.

Annotation flags computed for this component are `SkAnnotation_reflected_cpp` and instances are only embedded for `SkAnnotation_reflected_data`.

**To Reproduce**
1. Make C++ subclass of BoxComponent (Sub)
2. Add Sub to any BP actor
3. Create a non-empty constructor in Sub
4. Create a BP callable sk function in Sub
5. Try to call function