[iOS] Replace address infobar if the 1st one has been accepted by the user

Before this CL:
The second address infobar would be ignored if there exists another
infobar irrespective of its visibility.

With this CL:
The address import infobar would be automatically declined when the first infobar is not visible(hidden behind the omnibox badge).
However, the second address infobar would replace the first address infobar if it is not visible at the moment, irrespective of whether the first one has been accepted by the user. This is particularly useful for the multistep form that ask for user's address details in sections.
See https://docs.google.com/document/d/1wssALJq-QktiPLjiehdfbDiNbWQSUKYPpK_T7r2MSy4/edit?usp=sharing for details.

Fixed: 1366381
Change-Id: I5643817b692114807eec44476ca832c9f513ff20
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3945506
Reviewed-by: Florian Leimgruber <fleimgruber@google.com>
Reviewed-by: Matthias Körber <koerber@google.com>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Chris Lu <thegreenfrog@chromium.org>
Commit-Queue: Vidhan Jain <vidhanj@google.com>
Cr-Commit-Position: refs/heads/main@{#1062806}