firebase_messaging clear instructions on how to use it with Kotlin

[i6x86]

I'm trying to implement the onBackgkround message handle but the instructions suppose that the project was created with java despite the default now is Kotlin.
So I created Application class in the kotlin folder but now there are a couple of errors saying:

Cannot access 'android.app.Application' which is a supertype of 'com.my.app.Application'.
and:
Cannot access 'java.lang.Object' which is a supertype of 'com.steepcode.mdd.Application'. Check your module classpath for missing or conflicting dependencies
I think it might has to do with the fact the my io.flutter.plugins folder is in folder named java and not in the kotlin one, but have no idea what to do.

[beshr-eldebuch]

Check out this Pull request