this is still up in the air, but it seems to be generally breaking such that police can force you to use fingerprints or faceID to unlock your phone because fingerprints and face scans are evidence, but you can refuse to give them a passcode because a passcode is testimony. so use passcodes, not biometrics.
Also nice to know, on an iPhone you can press power and volume up for a few second and then cancel the upcoming dialog. It will only be then require your pin to enable any other authentication method.
On recent almost all Androids from the last decade+ you can reboot them to force a PIN requirement, and lockdown mode is available on most recent Android phones, not just Pixel