Remove local_modifications from arm-neon-tests

It doesn't provide any useful information. Local changes can be found by:
git diff update_origin/master...aosp/master

Also external_updater doesn't support local_modification field for now.

Test: NA
Change-Id: I7ab58948b72403eef1bd855c75193cff8f096c25
diff --git a/METADATA b/METADATA
index b16ca91..1aa20de 100644
--- a/METADATA
+++ b/METADATA
@@ -13,6 +13,4 @@
   }
   version: "333ee3023f49a605e886e77c6e8c49bf655c81fb"
   last_upgrade_date { year: 2017 month: 11 day: 15 }
-
-  local_modifications: "Android.mk is created on basis of Makefile.  Some tests are disabled to prevent clang crash on buildbots."
 }