Make dexdiffer.py u+x

tools/android/dexdiffer/dexdiffer_unittest.py

+#!/usr/bin/env python
 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 """Tests for dexdiffer."""
 
 import dexdiffer
 import json
 import unittest
 
 
@@ skipping 166 matching lines @@
     self.assertDeepEqual(actual, expected)
 
   def assertDeepEqual(self, actual, expected):
     # Only designed to work for json-able types
     a = json.dumps(actual, sort_keys=True)
     e = json.dumps(expected, sort_keys=True)
     self.assertEqual(a, e)
 
 if __name__ == '__main__':
   unittest.main()