Use binary mode for proto ingestion

Bug: webrtc:13607
Change-Id: Id0385f74215360ff604641a50ce9f599c87abb5e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/251327
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Christoffer Jansson <jansson@google.com>
Cr-Commit-Position: refs/heads/main@{#35960}

tools_webrtc/perf/catapult_uploader.py

@@ -195,8 +195,8 @@ def _ApplyHacks(dicts):
 
 def _LoadHistogramSetFromProto(options):
   hs = histogram_set.HistogramSet()
-  with options.input_results_file as f:
-    hs.ImportProto(f.read().decode('utf-8'))
+  with open(options.input_results_file, 'rb') as f:
+    hs.ImportProto(f.read())
 
   return hs