[CfT] Only hide infobars that don't require confirmation

CL https://crrev.com/c/5012709 disabled all infobars including
the ones that require confirmation thus making certain operations
impossible if --disable-infobars switch is specified.

This CL changes --disable-infobars behavior so that it only
disables infobars that don't have buttons on them
(although they may have an active URL).

Note that in headless mode all infobars are still disabled
even if --disable-infobars is not specified. This is because
no one can see or act on them anyway.

Bug: 333945848
Change-Id: I503b013d39e8182c188886a48263f1f36c112b4d
Cq-Include-Trybots: luci.chromium.try:linux-rel-cft,mac-rel-cft,win-rel-cft
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5455939
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Peter Kvitek <kvitekp@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1288766}