VCN 3DS update query param to shouldProceed

The new alignment with the server team is that the query param that
denotes whether the authentication completed or not is "shouldProceed",
instead of "isComplete". This CL updates that logic accordingly.

Bug: 41490740
Change-Id: I29c66c42f7c7f192360c540045dee4f4280fadc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5411052


Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Reviewed-by: Siyu An <siyua@chromium.org>
Commit-Queue: Vinny Persky <vinnypersky@google.com>
Reviewed-by: Jan Keitel <jkeitel@google.com>
Cr-Commit-Position: refs/heads/main@{#1282498}