Java has nulls, and any object reference in Java can be null, but in Kotlin parameters default to not null unless the type is specified as `Type?`; our override of onActivityResult was specifying the type of the intent parameter as `Intent` instead of `Intent?`, causing an exception before our code was called. Figuring out how to turn on "break on all exceptions" in Android Studio (which is non-trivial for some reason) finally showed me the stack trace.
* Implement the mechanics of fxa login on android, but don't show ui for it yet. Also, scopedKeys are not yet implemented.
* Hopefully fix the package-lock conflict?
* WIP on android scoped keys
* Finish implementing login.
* created android/user.js to handle android logins
