Hide the details of OPTIMIZATION_GUIDE_LOG as used in zero_state sources

This is just to make these files a bit easier to read by removing a
couple of lines from each log site.

Change-Id: Iaaba19025a35c50fea766c8d38302a892e4aa213
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6828683
Auto-Submit: Ian Wells <iwells@chromium.org>
Reviewed-by: Sophie Chang <sophiechang@chromium.org>
Commit-Queue: Ian Wells <iwells@chromium.org>
Commit-Queue: Sophie Chang <sophiechang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1499080}