Revert "crash_dump: temporarily make permissive."

This reverts commit 9cfe34b5.

Bug: http://b/34978531
Change-Id: I0702641c48fad273f16fa1a5f0e4483dfe408c05

private/crash_dump.te

-### HACK: Make crash_dump permissive temporarily to catch denials without breaking backtraces.
-userdebug_or_eng(`
-  permissive crash_dump;
-')