错误：无法解决：androidx.support：support-v7：28.0.0 Android

我已经镜像到AndroidX，但是仍然会发生此错误。

dependencies {
    implementation 'com.google.android.gms:play-services-auth:17.0.0'
    implementation 'com.google.android.gms:play-services-plus:17.0.0'
    implementation fileTree(dir: 'libs', include: '*.jar')
    implementation project(':beacon_controller:BluetoothLe')
    implementation project(':beacon_controller:BluetoothLe')
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'com.facebook.android:facebook-android-sdk:4.6.0'
    implementation 'androidx.recyclerview:recyclerview:1.1.0'
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'com.android.support:support-v7:28.0.0'

}