How to build a unity project to the same android project?

How can I build and export to the same android studio project without having to copy all the files again and again? Like if I make a small change in he c# script do I have to export the whole project again and then add all the native activities etc in it? That would be a headache.

Build Android project from Unity to another folder. Then copy only assets folder (/app/src/main/assets) from there to your original Android project. (delete assets folder in original project before copying)

That way only changes in Unity will be transferred to your Android project, and everything else will stay same.