How to stop apps being deleted

Autistic son has just informed me that the way he keeps removing Norton’s from his android device, despite the App Lock being on, is simply to drag it and mobile security icons to the trash can at the top of the screen. How can we stop him doing that.
Wondered how he was able to get past the App Lock Pin so easily!

You can also create different Android user profiles on the device. NMS when you install has an option to also install as a device administrator, a setting you can also lock down as well. That would not allow NMS be uninstalled unless its removed as an admin. 

A variety of ways you can go about it, depending on the version of Android you have.

Moving the app's icon from the home page to the trash can does not remove the app from the device. You can check this by looking at the full list of apps by tapping on the icon just above the home icon, or opening the Android Settings - Apps. Scroll down and you will still see that NMS is still installed and running.

If you have App Lock on the device, be sure you lock the Android Settings. And if you are concerned about your son not being to bypass things, I assume you have not given him the App Lock PIN.