Preinstalled Apps: give warning that removing the app is for all users

When having multiple users on a device, it isn't immediately apparent that removing an app from "Preinstalled Apps" will remove the app for all users. I am not sure where the best place to put the warning would be, but it would be good to make sure users are aware of this.

https://community.iode.tech/t/bug-add-new-user-setup-app-selection-affects-first-account-instead-of-new-one/7322/3?u=rik