[Android][telemetry] Update pylib imports for modules that moved into devil.

build/android/pylib/junit/test_runner.py

 # Copyright 2014 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.
 
 import json
 import os
 import tempfile
 
-from pylib import cmd_helper
+from devil.utils import cmd_helper
 from pylib import constants
 from pylib.base import base_test_result
 from pylib.results import json_results
 
 class JavaTestRunner(object):
   """Runs java tests on the host."""
 
   def __init__(self, args):
     self._package_filter = args.package_filter
     self._runner_filter = args.runner_filter
@@ skipping 21 matching lines @@
       if self._sdk_version:
         command.extend(['-sdk-version', self._sdk_version])
       return_code = cmd_helper.RunCmd(command)
       results_list = json_results.ParseResultsFromJson(
           json.loads(json_file.read()))
       return (results_list, return_code)
 
   def TearDown(self):
     pass