Fix multi-locale issues

- Don't ignore LOCALE_CHANGED sent when CP2 is already updating
locales.

- Don't add multiple Chinese locales.

- Don't add any Chinese locales after Japanese.

- Also fix the flakiness in the test.

Bug 31115382

Change-Id: Ib17d08f7947cb02aa7052d8ed6b67690361c47bf
4 files changed