Avoid calling into package manager while holding permission lock.

Since we are moving permission into mainline, the permission module
may be called with any lock held in (customized) platform code, so we
should not try to acquire any lock while holding our own lock to
prevent deadlock.

Bug: 158736025
Test: LockFinder
Test: presubmit
Change-Id: If353c03d785bddddfcf6a4d66af70d91f9a957e4