一些项目缺少 AndroidManifest 文件, 比如说 flutter_widget_of_the_week about flutter-notebook HOT 6 CLOSED

D:\Code\github\flutter\Flutter-Notebook-master\mecury_project\example\animated_floating_action_bar\android\app\src\main\java\com\litavadaski\animatedfloatingactionbar\MainActivity.java:11: ����: �����ݵ�����: MainActivity�޷�ת��ΪFlutterEngine
    GeneratedPluginRegistrant.registerWith(this);
                                           ^
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FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 6s
Finished with error: Gradle task assembleDebug failed with exit code 1

D:\Code\github\flutter\Flutter-Notebook-master\mecury_project\example\animated_floating_action_bar\android\app\src\main\java\com\litavadaski\animatedfloatingactionbar\MainActivity.java:11: 错误: 不
兼容的类型: MainActivity无法转换为FlutterEngine
    GeneratedPluginRegistrant.registerWith(this);

package com.litavadaski.provider_example;

import android.os.Bundle;
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugins.GeneratedPluginRegistrant;

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

  @Override
  public void configureFlutterEngine(FlutterEngine flutterEngine) {
    GeneratedPluginRegistrant.registerWith(flutterEngine);
  }
}