Reduce scope of annotation tests on Windows FYI bot.

Network traffic annotation tests on Windows FYI bot are failing. The
scope of tests is reduced to minimum to check for error.

TBR=georgesak@chromium.org

Bug: 844014
Change-Id: Ib6ea2b50cc4bf5ca2c869daf7e133f0feac790f3
Reviewed-on: https://chromium-review.googlesource.com/1098655Reviewed-by: Ramin Halavati <rhalavati@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566795}

tools/traffic_annotation/scripts/traffic_annotation_auditor_tests.py

@@ -50,6 +50,11 @@ class TrafficAnnotationTestsChecker():
       ["--test-only", "--no-filtering"]      # Not using heuristic filtering.
     ]
 
+    # TODO(https://crbug.com/844014): Remove after debugging on
+    # win-annotator-rel.
+    if sys.platform == 'cygwin' or sys.platform.startswith('win'):
+      configs = configs[:1]
+
     last_result = None
     for config in configs:
       result = self._RunTest(config)