Why is this still not a thing, its the ultimate secure combo. Paired with autoreboot after no unlock for X hours its perfect. Fingerprint for unlock is just fundamentally shit.
This is copying a similar feature Apple added a while back.
Given androids hardware situation and love for collecting all the data l, I understand why people don't want to give biometrics to their Android devices.
With the data and access our smartphones have, a numerical pin regardless of length, should not be an option anymore.
I am surprised that neither platform is allowing voice authentication as a biometric. I'm not sure if Google supports it but Siri can already tell who is speaking.