[CodeHealth] Migrate base::Value to v2 in components/invalidation/impl/

This change is part of the base::Value refactor to v2 API.

Bug: 1303949
Change-Id: I31d4bb8b3f2ced38e0fe0ba6e4ca826eae1bbbed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4412894


Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Andy Phan <andyphan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1128693}