[WebAuthn][Passwords] Disable biometric auth promo for WebAuthn windows

If
1. the enclave authenticator needs a MagicArch prompt
2. PWM has a GAIA credential stored
3. the device has biometrics available and the user has not opted in

PWM will show the biometric opt-in bubble (screen/4RmZHMHcuHeEQ2B) in
the MagicArch WebView! This is undesired.

This CL fixes it by checking the last committed URL in PWM Client.
The kdi parameter is specific to GPM enclave.

Bug: 40274370
Change-Id: Ied4fba92d31e6d1ad62c21106bd9177b6ff535eb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5573567
Commit-Queue: Adem Derinel <derinel@google.com>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Adam Langley <agl@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1306625}