How do I get rid of boot screen on unrooted phone?

I have an old Samsung galaxy a5 2016 (sm-a510f). I had previously rooted it and installed a custom ROM called the Google Product Rom along which came a boot animation that flashed the google logo before actually going into the animation. Now I have decided to unroot the phone and flash the stock firmware, I have managed to do everything including getting rid of the boot animation. But when I boot up the phone it still flashes the Google logo before going on to play the Samsung boot animation. How do I get rid of it without having to re-root my phone? If there is no way and I have to root my phone again! How do I achieve this on a rooted device?