Fix sbox_validation_tests & Make isolate_driver.py include the executable itself

chrome/installer_util_unittests.isolate

 # Copyright 2015 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.
 {
   'conditions': [
     ['OS=="win"', {
       'variables': {
         'command': [
           '<(PRODUCT_DIR)/installer_util_unittests.exe',
         ],
         'files': [
-          '<(PRODUCT_DIR)/installer_util_unittests.exe',
           'test/data/extensions/',
           'test/data/installer/',
         ],
       },
     }],
   ],
   'includes': [
     '../base/base.isolate',
   ],
 }