language_packs: Extend histogram expiries

These metrics are useful for investigating issues with language packs,
and have previously been used to resolve significant incidents. Extend
all histogram expiries to 2026-01-04 to match the other expiries.

Fixed: 433259004, 433258671, 433258096, 433258213, 433258392
Change-Id: I6a6a2100c8911edf31e63e341c62a4588d0cbd2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6774107
Reviewed-by: Tony Yeoman <tby@chromium.org>
Commit-Queue: Tony Yeoman <tby@chromium.org>
Auto-Submit: Michael Cui <mlcui@google.com>
Reviewed-by: Bao-Duy Tran <tranbaoduy@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1496131}