Add vivo FIDO client (com.fido.client) to privileged apps

[zy6p]

This PR adds the preinstalled vivo FIDO / passkey client com.fido.client to the privileged apps list consumed by Keyguard (via .github/update_gpm_passkeys_priv_apps.py).

On recent vivo devices (OriginOS / Android 14), passkey flows routed through the system FIDO UI (com.fido.client) can fail in passkey providers with errors like:

The calling app 'com.fido.client' is not on the privileged list and cannot request authentication on behalf of the other app.

By trusting com.fido.client (package name + SHA-256 cert fingerprint), Keyguard can successfully complete passkey registration and authentication when the vivo system FIDO UI mediates the request. This change is aligned with a similar community contribution to Bitwarden:
bitwarden/android#6114

Verification:

• Set Keyguard as the default passkey provider on a vivo device.
• Use https://passkeys.io / https://webauthn.io with QR / cross-device sign-in.
• Confirm that passkey registration and authentication via com.fido.client succeed after this change.

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[zy6p]

I have read the CLA Document and I hereby sign the CLA