Log metrics for Save card Infobar Modal on iOS. (2/2)

This CL records how Save Card offer is denied specifically through
Infobar “Modal” dismissal. The modal could be dismissed through the
“Cancel" button or by clicking the link.

Before this CL, dismissal of modal in offer state (before being
accepted) was never recorded.

Bug: 394613272, 396707203, 352467351
Change-Id: Idfdc8c52f38056a0c4351dd7436df101a296bbee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6271564
Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Reviewed-by: Tommy Martino <tmartino@chromium.org>
Commit-Queue: Kavita Soni <kavitasoni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1423499}