Flutter 项目 Your app isn't using AndroidX错误

[!] Your app isn't using AndroidX.
    To avoid potential build failures, you can quickly migrate your app by following the steps on https://goo.gl/CP92wY.

这个提示是说项目并没有使用AndroidX

 

然后项目会接着报如下的一堆错误，其实就是没有使用AndroidX的问题

Attribute application@appComponentFactory value=(android.support.v4.app.CoreComponentFactory) from [com.android.support:support-compat:28.0.0] AndroidManifest.xml:22:18-91
	is also present at [androidx.core:core:1.1.0] AndroidManifest.xml:24:18-86 value=(androidx.core.app.CoreComponentFactory).
	Suggestion: add 'tools:replace="android:appComponentFactory"' to <application> element at AndroidManifest.xml:9:5-32:19 to override.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:processDebugManifest'.
> Manifest merger failed : Attribute application@appComponentFactory value=(android.support.v4.app.CoreCompo