pw_trace: log extra event data as hex bytes

Testing done:
- tested with my target

Change-Id: I18948f83518455fa9744f08b7077279c1408d262
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/20282
Commit-Queue: Paul Mathieu <paulmathieu@google.com>
Reviewed-by: Rob Oliver <rgoliver@google.com>
diff --git a/pw_trace/py/pw_trace/trace.py b/pw_trace/py/pw_trace/trace.py
index 4a57592..c3e3a57 100755
--- a/pw_trace/py/pw_trace/trace.py
+++ b/pw_trace/py/pw_trace/trace.py
@@ -140,6 +140,8 @@
                 for i, item in enumerate(items):
                     args["data_" + str(i)] = item
                 line["args"] = args
+            else:
+                line["args"] = {"data": event.data.hex()}
 
         # Encode as JSON
         json_lines.append(json.dumps(line))