Also scan stderr for audio files to test, due to change in Android test_runner

webrtc/audio/test/low_bandwidth_audio_test.py

 #!/usr/bin/env python
 # Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 """
@@ skipping 180 matching lines @@
   example_path = os.path.join(SRC_DIR, 'resources',
                               'voice_engine', 'audio_tiny48.wav')
   if _RunPolqa(polqa_path, example_path, example_path):
     analyzers.append(Analyzer(_RunPolqa, polqa_path, 48000))
 
   for analyzer in analyzers:
     # Start the test executable that produces audio files.
     test_process = subprocess.Popen(
         _LogCommand(test_command + ['--sample_rate_hz=%d' %
                                     analyzer.sample_rate_hz]),
-        stdout=subprocess.PIPE)
+        stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
     try:
       lines = iter(test_process.stdout.readline, '')
       for result in ExtractTestRuns(lines, echo=True):
         (android_device, test_name, reference_file, degraded_file) = result
 
         adb_prefix = (args.adb_path,)
         if android_device:
           adb_prefix += ('-s', android_device)
 
         reference_file = _GetFile(reference_file, out_dir,
@@ skipping 11 matching lines @@
           os.remove(reference_file)
           os.remove(degraded_file)
     finally:
       test_process.terminate()
 
   return test_process.wait()
 
 
 if __name__ == '__main__':
   sys.exit(main())