Remove unused dalvik.vm.stack-trace-dir.

Bug: http://b/73140330
Test: boots
Change-Id: I8fd27c6eb8c99870cb77019ae06bdb46a934ffc9

public/property_contexts

@@ -55,7 +55,6 @@ dalvik.vm.method-trace-file u:object_r:exported_dalvik_prop:s0 exact string
 dalvik.vm.method-trace-file-siz u:object_r:exported_dalvik_prop:s0 exact int
 dalvik.vm.method-trace-stream u:object_r:exported_dalvik_prop:s0 exact bool
 dalvik.vm.profilesystemserver u:object_r:exported_dalvik_prop:s0 exact bool
-dalvik.vm.stack-trace-dir u:object_r:exported_dalvik_prop:s0 exact string
 dalvik.vm.usejit u:object_r:exported_dalvik_prop:s0 exact bool
 dalvik.vm.usejitprofiles u:object_r:exported_dalvik_prop:s0 exact bool
 dalvik.vm.zygote.max-boot-retry u:object_r:exported_dalvik_prop:s0 exact int