This won't stop the cops from hacking into your phone with celebrite, but android has a feature called lockdown mode that will disable facial recognition, fingerprints, and voice ID until your phone is unlocked via PIN. I need to unlock my phone quickly throughout the day, so I use fingerprint - but I use lockdown if I get pulled over or am going through security, etc. It isn't perfect, but it's better (for me) than having to enter a long PIN every time I need to unlock my phone.
Once you enable it in settings, you can take your phone to the power off/restart menu and enable lockdown.
Using Tasker, you could probably disable quick unlock when outside of your house, etc.
Do a restart (even if you have to hold the power button for 10 seconds). Because at initial boot state, the contents of your phone are encrypted. Any unlocks after the initial unlock, your phone is decrypted and the key is in RAM. Only a password/pin (no fingerprint/FaceID/etc) can be used to decrypt your data.
In lockdown mode, my understanding is that you're simply disabling biometrics (but not encrypting anything).
Thank you. I say it because I was genuinely asking the person who replied to me, in case I was wrong. In the context of privacy, it's extremely important to know for sure.
But none of that is going to stop them from detaining you until you give them the pin.
US citizens might have it a little easier. But foreigners are certainly going to regret their choices if anyone ‘close’ to the border has an issue with them.