Type mismatch: inferred type is PluginRegistry but FlutterEngine was expected

Question

I am trying to use geofencing package in my flutter application. I have installed it and did all the config to handle permission and register a background service. Here is my manifest file:

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.geofencing">
  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
  <uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />


  <application android:name=".Application" android:label="geofencing" android:icon="@mipmap/ic_launcher">
    <activity android:name=".MainActivity" android:launchMode="singleTop" android:theme="@style/LaunchTheme" android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode" android:hardwareAccelerated="true" android:windowSoftInputMode="adjustResize">
 
      <meta-data android:name="io.flutter.embedding.android.NormalTheme" android:resource="@style/NormalTheme" />

      <meta-data android:name="io.flutter.embedding.android.SplashScreenDrawable" android:resource="@drawable/launch_background" />
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <!-- Don't delete the meta-data below.
             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
    <meta-data android:name="flutterEmbedding" android:value="2" />

    <receiver android:name="io.flutter.plugins.geofencing.GeofencingBroadcastReceiver" android:enabled="true" android:exported="true" />
    <service android:name="io.flutter.plugins.geofencing.GeofencingService" android:permission="android.permission.BIND_JOB_SERVICE" android:exported="true" />
  </application>
</manifest>

Now in the documentation of package it's written that I need to create an Application class in the same folder as MainActiviy and reference it in manifest file which is exactly what I am doing. Below is my Appliction.kt file:

import io.flutter.app.FlutterApplication
import io.flutter.plugin.common.PluginRegistry
import io.flutter.plugins.GeneratedPluginRegistrant
import io.flutter.plugins.geofencing.GeofencingService

class MyApp : FlutterApplication(), PluginRegistry.PluginRegistrantCallback {
    override fun onCreate() {
        super.onCreate();
        GeofencingService.setPluginRegistrant(this)
    }

    override fun registerWith(registry: PluginRegistry) {
        GeneratedPluginRegistrant.registerWith(registry);
    }
}

When I try to build the project I get this exception:

Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
e: /home/user/flutter projects/geofencing_flutter/android/app/src/main/kotlin/com/example/geofencing/Application.kt: (13, 48): Type mismatch: inferred type is PluginRegistry but FlutterEngine was expected

How can I solve this problem?