sandwich: Fix some trivial failures on SWR benchmark runs

tools/android/loading/sandwich_utils.py

Index: tools/android/loading/sandwich_utils.py
diff --git a/tools/android/loading/sandwich_utils.py b/tools/android/loading/sandwich_utils.py
index b5ec4979d2d0b4db94e1f87eddf724ea8f15cdae..eda55e03dba27237aab59aec8e3c7ba95963eb0b 100644
--- a/tools/android/loading/sandwich_utils.py
+++ b/tools/android/loading/sandwich_utils.py
@@ -35,6 +35,8 @@ def FilterOutDataAndIncompleteRequests(requests):
     if request.protocol is None:
       assert not request.HasReceivedResponse()
       continue
+    if request.protocol in {'about'}:
+      continue
     if request.protocol not in {'http/0.9', 'http/1.0', 'http/1.1'}:
       raise RuntimeError('Unknown request protocol {}'.format(request.protocol))
     yield request