Entire react native app showing on lockscreen

I have an app with the following code on the MainActivity.java:

package com.MyApp;

import com.facebook.react.ReactActivity;
import com.facebook.react.ReactActivityDelegate;
import com.facebook.react.ReactRootView;
import com.swmansion.gesturehandler.react.RNGestureHandlerEnabledRootView;
import android.view.Window;
import android.view.WindowManager;
import android.os.Bundle;
import com.MyApp.CustomLockscreenPackage; 

public class MainActivity extends ReactActivity {

    @Override
    protected String getMainComponentName() {
        return "MyApp";
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Window w = getWindow();
        w.setFlags(
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED,
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
        );
    }

    @Override
    protected ReactActivityDelegate createReactActivityDelegate() {
        return new ReactActivityDelegate(this, getMainComponentName()) {
            @Override
            protected ReactRootView createRootView() {
                return new RNGestureHandlerEnabledRootView(MainActivity.this);
            }
        };
    }
}

The lines who make the app work on the lockscreen are:

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Window w = getWindow();
        w.setFlags(
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED,
            WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
        );
    }

But, the entire app works on the lockscreen, and i need to make only certain screens works on the lockscreen (It's a call app). I tried creating a native module but don't worked. i know its possible remove the flags with:

getWindow().clearFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);

So, if i can call these lines on my react native screen, it probably can work