Android - home screen lifecycle

I am developing android home screen, I seem to be having problems. Whenever I launch the app from this home screen, its lifecycle ends up being destroyed (I knew this because I was using LogCat and it prints my code in the OnDestroyed method). I only want this to be paused but not completely destroyed because I am running multiple long processes in oncreate. I only wanted onCreate to be called once when the device is loaded. In my case, because whenever my home screen launches the app, it gets destroyed. And whenever I press the HOME button it goes from the create -> on start -> on resume function. Below are my codes, can you state that I am doing something wrong. Thank.

My code when starting the application:

public void startAppByAppName(String appName) {
    String mainActivity = "";
    String packageString = "";

    Intent intent = getPackageManager().getLaunchIntentForPackage(appName);
    mainActivity = intent.getComponent().getClassName();
    packageString = intent.getComponent().getPackageName();

    intent.addCategory(Intent.CATEGORY_LAUNCHER);
    intent.setComponent(new ComponentName(packageString, mainActivity));
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    startActivity(intent);
}

      

        
        
        
      

    

My manifest:

<application
    android:allowBackup="true"
    android:icon="@drawable/home_icon"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" android:persistent="true">
    <activity 
        android:name="com.steven.welcomescreen.WelcomeScreenActivity"
        android:launchMode="singleTask"
        android:clearTaskOnLaunch="true"
        android:stateNotNeeded="true"
        android:screenOrientation="landscape"
        android:theme="@android:style/Theme.Black.NoTitleBar">
        <intent-filter>
            <category android:name="android.intent.category.HOME"/>
            <action android:name="android.intent.action.MAIN"/>
            <category android:name="android.intent.category.DEFAULT"/>
        </intent-filter>
    </activity>
</application>

      

        
        
        
      

    

If there are some parts of my code that you want to clarify, just write below so that I can provide you with information. I really need help. Thank you very much.