Revert "Add additional vlogging for origin-agent-cluster decisions."

This reverts commit 877d37961a2e5ac58ea65883db3bf431bdbe457e.

Reason for revert: The additional logging was meant to be temporary, to help diagnosing a bug. The underlying issue has meanwhile been resolved and this code no longer serves a purpose.

Original change's description:
> Add additional vlogging for origin-agent-cluster decisions.
>
> This adds temporary logging to aid debugging 1429587. The intent is
> to get this into a canary build and then revert this CL again.
>
> Intended use:
>   .../chrome --enable-logging=stderr --vmodule=navigation_request=2 \
>     --log-level=3
>
> Bug: 1429587
> Change-Id: Ie22eea0603eaf8c9c1ea1c902f2768638e8cefd7
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4442346
> Reviewed-by: Camille Lamy <clamy@chromium.org>
> Commit-Queue: Daniel Vogelheim <vogelheim@chromium.org>
> Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
> Cr-Commit-Position: refs/heads/main@{#1136117}

Bug: 1429587
Change-Id: Id35c93c9179a660d7e0a91103d7757f60b4b6893
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4562036
Commit-Queue: Daniel Vogelheim <vogelheim@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1151978}