[Telemetry] Move discover to common/py_utils

telemetry/telemetry/internal/platform/profiler/profiler_finder.py

 # Copyright 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.
 
 import os
 
-from telemetry.core import discover
 from telemetry.internal.platform import profiler
 from telemetry.core import util
 
+from py_utils import discover
 
 def _DiscoverProfilers():
   profiler_dir = os.path.dirname(__file__)
   return discover.DiscoverClasses(profiler_dir, util.GetTelemetryDir(),
                                   profiler.Profiler,
                                   index_by_class_name=True).values()
 
 
 def FindProfiler(name):
   for p in _DiscoverProfilers():
     if p.name() == name:
       return p
   return None
 
 
 def GetAllAvailableProfilers():
   return sorted([p.name() for p in _DiscoverProfilers()
                  if p.is_supported(browser_type='any')])