Revert "Perform SetEvent under the user_code_suspend_count_lock_"

This reverts commit 3fa8b6db7b556035f192d037b35210677250798e.

Bug: 130150240
Reason for revert: Causes lock-level violations on gcstress

Change-Id: Ie580be5658da63f951652ba74cfbf25fa845765c
4 files changed