Remove incorrect FuzzyPinyin entries in InputMethodSettings API.

This private API is meant for exclusive use by CrOS 1P Virtual
Keyboard (VK) + IME extension (in internal repo).

These FuzzyPinyin entries have schema mismatches with actual
CrOS-Prefs data that's backing the API and returned to clients.
They're thus futile and no longer used.

The API doesn't need to declare typings for all data entries;
only those needed by CrOS 1P VK+IME extension are required.

It's reasonable and preferable to first remove all broken
unused FuzzyPinyin entries first, before re-adding correct ones
and re-implementing FuzzyPinyin support in CrOS 1P VK.

Bug: b:458588376
Change-Id: I2166bb98c23c00ae2c560f9f36155dfe839204fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7141218
Commit-Queue: Bao-Duy Tran <tranbaoduy@chromium.org>
Reviewed-by: Darren Shen <shend@chromium.org>
Reviewed-by: Jimmy Gong <jimmyxgong@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1546296}
NOKEYCHECK=True
GitOrigin-RevId: 8fd54882bf8eac51edbf866b3e6e42bc508719da