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

build/android/pylib/flag_changer.py

 # Copyright (c) 2012 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 logging
 
-from pylib.device import device_errors
+from devil.android import device_errors
 
 
 class FlagChanger(object):
   """Changes the flags Chrome runs with.
 
   There are two different use cases for this file:
   * Flags are permanently set by calling Set().
   * Flags can be temporarily set for a particular set of unit tests.  These
     tests should call Restore() to revert the flags to their original state
     once the tests have completed.
@@ skipping 133 matching lines @@
 
     # Tack on the last flag.
     if not current_flag:
       if within_quotations:
         logging.warn('Unterminated quoted argument: ' + line)
     else:
       tokenized_flags.append(current_flag)
 
     # Return everything but the program name.
     return tokenized_flags[1:]