Use new LocalisationCacheRecacheFallback hook

This allows us to not use the wrong message when a language itself
doesn't have a change but one of its fallbacks does.

Bug: 68781
Change-Id: I5433aeba95823c5e939efc5e304d955faf1e9551
(cherry picked from commit 10d82302d02a5cbeb2ad687342e5ca6cc962bd92)