CredentialProvider/MyVault: Passkey registration with RP fails in Google Chrome

Passkey registration fails in Chrome while it works in Firefox on Android.

The error shown in Chrome is: An unknown error occurred while talking to the credential manager.

I tried with different WebAuthn demo/debugging pages, all displaying the same error message:

https://webauthn.io
https://ctap.dev/

Using:

identity-samples https://github.com/android/identity-samples/commit/a28e5adc475bdb85e40ac852faf4d59e1a890695
device: Samsung S10 Ultra, Android 16

Reproduce passkey registration in Google Chrome on the reported Samsung S10 Ultra running Android 16, using the identity-samples commit a28e5adc475bdb85e40ac852faf4d59e1a890695. Compare the result with Firefox and the reported WebAuthn demo pages at webauthn.io and ctap.dev. Done means identifying why Chrome reports the credential-manager error and documenting or fixing the registration failure.

Written by the indexing model from the issue text.