Fix lock contention in CAO.binderError handler

CAO.binderError handler already has a local copy of frozen pids. It's
not necessary to hold Freezer lock. Holding the Freezer lock here
actually causes lock contention as the CAO thread might be preempted for
multiple seconds, blocking unfreeze operations in freezeHandler.

Bug: 323393888
Test: frozen apps receiving unexpected binder transactions can be killed
Change-Id: I8d6f1b2327dae76b61ef6f4d7f39d66a85f313f1