[BUG] Can't select blittable types as `object` / `Object` inheritors

[Antoshidza]

What happened?

[SerializeReference, SubclassSelector] private Object _params;

This field let me select any type accessible from unity But I can't select int / float / bool / etc. Also ValueType doesn't get serialized at all. It is strange, because those blittable types are object -> ValueType -> inheritors and should exist in System namespace.

Package Version

1.4.0

Unity Version

6000.0.19f1