[Federated] Fix small typo.

Test: n/a
Bug: n/a
Change-Id: I91b7b6ba643557a9356cdc9c82a3679854a84e2a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4624198


Reviewed-by: Xinglong Luan <alanlxl@chromium.org>
Auto-Submit: Amanda Deacon <amandadeacon@chromium.org>
Commit-Queue: Xinglong Luan <alanlxl@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1162683}