Lengthened threadname formatting to allow for longer serial numbers

BUG=b:37486665
TEST=Ran on a testbed with a 12-char serial number
Change-Id: I7fe8b6565fba021abf5993ffbf06cd0f1c85ed76
Reviewed-on: https://chromium-review.googlesource.com/508230
Commit-Ready: Kris Rambish <krisr@chromium.org>
Tested-by: Kris Rambish <krisr@chromium.org>
Reviewed-by: Kris Rambish <krisr@chromium.org>
Reviewed-by: Dan Shi <dshi@google.com>
diff --git a/client/common_lib/logging_config.py b/client/common_lib/logging_config.py
index 711587e..bc83328 100644
--- a/client/common_lib/logging_config.py
+++ b/client/common_lib/logging_config.py
@@ -50,7 +50,7 @@
                    '%(lineno)4.4d| %(message)s')
     FILE_FORMAT_WITH_THREADNAME = (
             '%(asctime)s.%(msecs)03d %(levelname)-5.5s|%(module)18.18s:'
-            '%(lineno)4.4d| %(threadName)10.10s| %(message)s')
+            '%(lineno)4.4d| %(threadName)16.16s| %(message)s')
     DATE_FORMAT = '%m/%d %H:%M:%S'
 
     file_formatter = logging.Formatter(fmt=FILE_FORMAT, datefmt=DATE_FORMAT)