Correct typo of Chinese locale zn_CN to zh_CN

Bug: chromium:1051186, chromium:1064326
Change-Id: Ied8d264ac3a40635f13ce09b2009135eaeb0118b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2158485Reviewed-by: Dan Elphick <delphick@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67264}

test/cctest/test-api-icu.cc

@@ -45,9 +45,9 @@ TEST(LocaleConfigurationChangeNotification) {
   isolate->LocaleConfigurationChangeNotification();
   CheckLocaleSpecificValues("ru-RU", "14.02.2020, 13:45:00", "10 000,3");
 
-  SetIcuLocale("zn_CN");
+  SetIcuLocale("zh_CN");
   isolate->LocaleConfigurationChangeNotification();
-  CheckLocaleSpecificValues("zn-CN", "2020-2-14 13:45:00", "10,000.3");
+  CheckLocaleSpecificValues("zh-CN", "2020/2/14 下午1:45:00", "10,000.3");
 
   UErrorCode error_code = U_ZERO_ERROR;
   icu::Locale::setDefault(default_locale, error_code);