The ICU API for maximizing and minimizing a locale ID takes ICU format locale id as an input
so that a BCP 47 language tag must be converted to the corresponding ICU locale id.

Bug: v8:7982
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I1cb1dacbf057bbc8bb8beb9b62d1ec4becd82624
Reviewed-on: https://chromium-review.googlesource.com/1150934Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Jungshik Shin <jshin@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55768}