Android lock issues in custom lock screen app

I created a custom screen lock application that uses a broadcast receiver and a listening service when a user turns the screen on or off and starts my activity from there. It is assumed that activity will completely replace the lock screen. To do this, my application must disable Android lock so that my application can function as a new lock screen.

Instead, it happens that when the application is first installed, the service first started the application, it seems to be working. and when the user first turns off the screen of his phone, when he returns it, he will be represented by my application running from above and will be able to unlock his phone with my application. But then once inside the Android operating system, if the user presses the "home" button, the next time they turn off the screen and return it back, instead of returning to my application, they get to the stock unlock screen, while my application open under him when he should be on top.

Here is my code:

My service:

public class MyService extends Service {
    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void onCreate() {

        super.onCreate();
        Log.d("MyService","Service STARTED");
        final IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        final BroadcastReceiver mReceiver = new ScreenReceiver();
        registerReceiver(mReceiver, filter);
    }
}

My radio:

public class ScreenReceiver extends BroadcastReceiver {

public static ArrayList<String> runningApplications = new ArrayList<String>();
private Context ctext;
public static boolean screenIsLocked;
public static KeyguardManager keyguardManager;
public static KeyguardLock lock;

@Override
public void onReceive(final Context context, final Intent intent) {
    ctext = context;
    keyguardManager = (KeyguardManager)ctext.getSystemService(Activity.KEYGUARD_SERVICE);
    lock = keyguardManager.newKeyguardLock(Context.KEYGUARD_SERVICE);
    lock.disableKeyguard();


    if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
        screenIsLocked = true;
        Log.d("ScreenReceiver", "False");

        Intent intenti = new Intent();
        intenti.setClass(context, starterActivity.class);
        intenti.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        intenti.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(intenti);


    } else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
        screenIsLocked = false;
        Log.d("ScreenReceiver", "True");

                    Intent intenti = new Intent();
                    intenti.setClass(context, starterActivity.class);
                    intenti.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    intenti.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    context.startActivity(intenti);
    }
}

My activity, which is running, is mostly empty, with only one unlock button that triggers finish();when pressed.