Add ShouldShowBiometricAuthenticationBeforeFillingPromo for ChromeOS

The CL in itself is harmless since it just add an "unused" function.
There are other commits in the bug that, and that are upcoming that
will use this feature.

The CL also explicitly states the order in which we need the
operations to happen. Earlier we relied on C++ implicit
shortcut of boolean that the remaining conditions would not run. That
is fine, except that, at times, its not explicitly clear that order
matters.

BUG=b:362915479
BUG=367336383

Change-Id: I3f00d4d6462bf77c19dcfbb1016bdf77324cee6d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5865351
Commit-Queue: Hardik Goyal <hardikgoyal@chromium.org>
Reviewed-by: Ioana Pandele <ioanap@chromium.org>
Auto-Submit: Hardik Goyal <hardikgoyal@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1357070}