AndroidX compatibility : Migrating to AndroidX

[faisalramdan-id]

As we are not sure when this will be merged, you can adjust your pubspec.yaml in the meantime:

flutter_youtube:
    git:
      url: https://github.com/faisalramdan17/FlutterYoutube.git
      ref: android-x

Originally posted by @faisalramdan17 in https://github.com/PonnamKarthik/FlutterYoutube/pull/32#issuecomment-465854092

[jkmathew]

I think the PR has merged, this issue still valid?