[Requirement] AndroidX migration.

[songyiYu]

Hi~ Thank you for developing this plugin!

But I can't use your plugin because it is not migrated to AndroidX.

I got this error.

> Configure project :hardware_buttons
WARNING: API 'variant.getJavaCompile()' is obsolete and has been replaced with 'variant.getJavaCompileProvider()'.
It will be removed at the end of 2019.
For more information, see https://d.android.com/r/tools/task-configuration-avoidance.
To determine what is calling variant.getJavaCompile(), use -Pandroid.debug.obsoleteApi=true on the command line to display a stack trace.
         *********************************************************
WARNING: This version of device_info will break your Android build if it or its dependencies aren't compatible with AndroidX.
         See https://goo.gl/CP92wY for more information on the problem and how to fix it.
         This warning prints for all Android build failures. The real root cause of the error may be unrelated.
         *********************************************************
  Command: /Users/yusong-i/development/PassionIndicator/android/gradlew app:properties

Finished with error: Please review your Gradle project setup in the android/ folder.

[giantsol]

Hello @songyiYu ,
We've migrated to AndroidX in version 1.0.0

Thanks!