packages/flutter_tools/templates/module/android/host_app_common/app.tmpl/src/main/java/androidIdentifier/host/MainActivity.java.tmpl

package {{androidIdentifier}}.host;

import android.os.Bundle;
{{#useNewAndroidEmbedding}}
{{#androidX}}
import androidx.annotation.NonNull;
{{/androidX}}
{{^androidX}}
import android.support.annotation.NonNull;
{{/androidX}}
import dev.flutter.plugins.GeneratedPluginRegistrant;
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;

public class MainActivity extends FlutterActivity {
  @Override
  public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
    GeneratedPluginRegistrant.registerWith(flutterEngine);
  }
}
{{/useNewAndroidEmbedding}}
{{^useNewAndroidEmbedding}}
import io.flutter.app.FlutterActivity;
import io.flutter.plugins.GeneratedPluginRegistrant;

public class MainActivity extends FlutterActivity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    GeneratedPluginRegistrant.registerWith(this);
  }
}
{{/useNewAndroidEmbedding}}