Java 禁用的通知栏（状态栏）

我正在Android Studio中开发一个应用程序，希望禁用通知栏。我的代码在某些版本中有效，但在其他版本中无效。我尝试过添加AndroidManifest或将TYPE_SYSTEM_OVERLAY更改为TYPE_APPLICATION_OVERLAY之类的替代方法，但都不起作用

这是我的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.resolucion.launcher2">

    <uses-permission android:name="android.permission.REORDER_TASKS" />

    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Launcher2">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
                <category android:name="android.intent.category.HOME" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
    </application>


</manifest>

import androidx.appcompat.app.AppCompatActivity;

import android.app.ActivityManager;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Debug;
import android.util.Log;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().addFlags(WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        if (getSupportActionBar() != null) {
            getSupportActionBar().hide();
        }
        setContentView(R.layout.activity_main);
    }

    @Override
    protected void onPause() {
        super.onPause();
        ActivityManager activityManager = (ActivityManager) getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);

        activityManager.moveTaskToFront(getTaskId(), 0);
    }

    @Override
    public void onBackPressed(){
        PackageManager pm = getPackageManager();
        pm.clearPackagePreferredActivities(this.getPackageName());
        MainActivity.this.finish();
        System.exit(0);
    }
}