[Android] Fix environment variable handling in devil_env.

build/android/PRESUBMIT.py

 # Copyright (c) 2013 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.
 
 """Presubmit script for android buildbot.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts for
 details on the presubmit API built into depot_tools.
 """
 
@@ skipping 52 matching lines @@
 
   devil_test_env = dict(pylib_test_env)
   devil_test_env.update({
       'DEVIL_ENV_CONFIG':
           input_api.os_path.join(build_android_dir, 'devil_chromium.json')
   })
   output.extend(input_api.canned_checks.RunUnitTests(
       input_api,
       output_api,
       unit_tests=[
+          J('devil', 'devil_env_test.py'),
           J('devil', 'android', 'battery_utils_test.py'),
           J('devil', 'android', 'device_utils_test.py'),
           J('devil', 'android', 'fastboot_utils_test.py'),
           J('devil', 'android', 'md5sum_test.py'),
           J('devil', 'android', 'logcat_monitor_test.py'),
           J('devil', 'utils', 'cmd_helper_test.py'),
           J('devil', 'utils', 'timeout_retry_unittest.py'),
       ],
       env=devil_test_env))
   return output
 
 
 def CheckChangeOnUpload(input_api, output_api):
   return CommonChecks(input_api, output_api)
 
 
 def CheckChangeOnCommit(input_api, output_api):
   return CommonChecks(input_api, output_api)