[PA] Report Scheduler-Loop Quarantine Stats to UMA

Bug: 40947587
Change-Id: Iaec8d5c66322720024d008497b9d94085931b3d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5377424


Reviewed-by: Keishi Hattori <keishi@chromium.org>
Reviewed-by: Joe Mason <joenotcharles@google.com>
Commit-Queue: Mikihito Matsuura <mikt@google.com>
Cr-Commit-Position: refs/heads/main@{#1278797}