Mark network and audio telemetry collection rates as supported.

Also mark them as unlisted. Network and audio telemetry collection rates
will not be exposed to admins, the default rates should be used unless
otherwise was specified using server side config.

Bug: b:230119184
Change-Id: I33f38d3472e7ee81d7853c1a1155c70d598076ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3602555


Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Ahmed Nasr <anasr@google.com>
Cr-Commit-Position: refs/heads/main@{#995405}