[iOS] Enable Password Bottom Sheet by default

The Password Bottom Sheet feature is now approved for launch, so
enable it by default.

Bug: 327219521
Change-Id: I8759fec8262da7a31ffac986ed31a1e1c906c533
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5415093


Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Commit-Queue: Alexis Hétu <sugoi@chromium.org>
Reviewed-by: Tommy Martino <tmartino@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1281767}