[Amount Extraction][Browser] Do not trigger amount extraction if cvc
field gets clicked

Before this change, amount extraction gets triggered if any field from
credit card form gets clicked. After this change, if it is cvc that
gets clicked, amount extraction is not triggered any more. This request comes from PM, they don't want to show BNPL suggestion if CVC is clicked.

Bug: 400983566
Change-Id: I32001f4bc9c85ac86129e4a765b84144a13ffdca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6331507
Reviewed-by: Siyu An <siyua@chromium.org>
Reviewed-by: Vinny Persky <vinnypersky@google.com>
Reviewed-by: Christoph Schwering <schwering@google.com>
Commit-Queue: James Sun <jamessun@google.com>
Cr-Commit-Position: refs/heads/main@{#1433867}