AndroidJavaObject that ships with c# API

I have a Unity project that can be run on Windows and on Android. When it runs on an android it uses an AndroidJavaObject (unityPlugin, https://www.youtube.com/watch?v=0ahGeTNUPLM) for establishing a bluetooth connection. It is a .jar file that you place ina a prefabs/api folder. The instance is than made with AndroidJavaObject plugin = new AndroidJavaObject("com.example.unityplugin.DataGather")

Now I am making a c# API so others can use a preecompiled .dll in their own projects(for Bluetooth connection) without haveing to know about the details. It would be great if there was a way to include AndroidJavaObject-unityPlugin(classes.jar) into this API so it would also work on Android projects.

So I guess my question is: When making a class library in visual studio, how to include a unityPlugin into the project, so that user can call all of the Android-specific methods that are in this unityPlugin?

If you can sugest another aproach, please do so. THX