[Android] Prepare build/android/ for catapult+devil.

build/android/pylib/linker/setup.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.
 
 """Setup for linker tests."""
 
 import logging
-import os
-import sys
 
-from pylib import constants
+from pylib.constants import host_paths
 from pylib.linker import test_case
 from pylib.linker import test_runner
 
-sys.path.insert(0,
-                os.path.join(constants.DIR_SOURCE_ROOT, 'build', 'util', 'lib',
-                             'common'))
-import unittest_util # pylint: disable=F0401
+with host_paths.SysPath(host_paths.BUILD_COMMON_PATH):
+  import unittest_util # pylint: disable=import-error
 
 # ModernLinker requires Android M (API level 23) or later.
 _VERSION_SDK_PROPERTY = 'ro.build.version.sdk'
 _MODERN_LINKER_MINIMUM_SDK_INT = 23
 
 def Setup(args, devices):
   """Creates a list of test cases and a runner factory.
 
   Args:
     args: an argparse.Namespace object.
@@ skipping 26 matching lines @@
     all_test_names = [test.qualified_name for test in all_tests]
     filtered_test_names = unittest_util.FilterTestNames(all_test_names,
                                                         args.test_filter)
     all_tests = [t for t in all_tests \
                  if t.qualified_name in filtered_test_names]
 
   def TestRunnerFactory(device, _shard_index):
     return test_runner.LinkerTestRunner(device, args.tool)
 
   return (TestRunnerFactory, all_tests)