[WebAuthn] Allow internal transport on Windows

During discovery initialization on Windows, we remove all transports
except for Hybrid.

We need to enumerate internal transports as well for enclave usage.

Change-Id: I73febe39d9dfb70b9f7cc9f88f3fc863385ffddb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5405917


Reviewed-by: Martin Kreichgauer <martinkr@google.com>
Commit-Queue: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1280292}