I also accidentally paste random stuff into input boxes all the time.
Although I think at the point of some on-device program reading your browser history against your will, you’re gonna have bigger problems.
On android it is possible to give permissions "once" "while using the app" "always".
But whatsapp now only accepts the full camera access. If you set "ask every time" to indeed only make a picture once and then no camera access anymore, it refuses and sends you to the permission dialoge.