[python3] - Fix low_bandwidth_audio_test.py (take 2)

No-Presubmit: True
Bug: webrtc:13607
Change-Id: I2cab05888d52e8964fddce233ad2903d540125fb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/249991
Auto-Submit: Mirko Bonadei <mbonadei@webrtc.org>
Owners-Override: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Jeremy Leconte <jleconte@google.com>
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Cr-Commit-Position: refs/heads/main@{#35854}

audio/test/low_bandwidth_audio_test.py

@@ -123,7 +123,7 @@ def ExtractTestRuns(lines, echo=False):
   """
   for line in lines:
     if echo:
-      sys.stdout.write(line)
+      sys.stdout.write(line.decode('utf-8'))
 
     # Output from Android has a prefix with the device name.
     android_prefix_re = r'(?:I\b.+\brun_tests_on_device\((.+?)\)\s*)?'