Fix deadlock caused by two-threaded property controls

Two threaded property controls were introduced in ag/21063815 to prevent
DOS for power controls. However, this causes deadlocks, so limit the
second thread to just sys.powerctl messages.

Bug: 273785601
Test: Boots, power messages work
Ignore-AOSP-First: Security fix
Change-Id: Ie27dc3b0cd9e2d28e94f2ad398c55ee27bc35835
1 file changed