[iOS] Update expiration date for signiny histograms

Update expiration from 2025-03-02 to 2026-03-02 for:
- Signin.SSOAuth.GetIdentities.ErrorCode
- SigninSSOIdentityListRequestCacheState.*
- Signin.SSOIdentityListRequest.Duration.*

Fixed: 397218469, 391170742, 391170514
Change-Id: I2d98115467bf5b365759d8b8237ff5bf5a5255af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6275143
Commit-Queue: Ryan Sultanem <rsult@google.com>
Commit-Queue: Jérôme Lebel <jlebel@chromium.org>
Reviewed-by: Ryan Sultanem <rsult@google.com>
Auto-Submit: Jérôme Lebel <jlebel@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1421313}