On pixel, if you ever need to - press and hold the power button, select "lockdown".

(It might apply to other androids too, I don't know.)

You will now need a pin to unlock the phone. This disables the lock screen shortcut (camera, light, etc) as well.

Why disable your convence features for an scenerio that is not likely and can be quickly and easily be prevented.

Universal: You could also just the tap the sensor with a "wrong" finger a few time, and the pin will be required.

Maybe don't do this one in front the cops...if you find your self in a postion where they are trying to unlock your phone, you probably don't want to piss them off. .

Edit: I'm surprised no one called me out on "if you're ever need to". The sentence was going to be "if you're even in a situation that needs...", but that was getting too long. Forgot to change you're to you.