Merge pull request #12177 from jtattermusch/run_tests_better_flake_query

auto_set_flakes should respect platform
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index a695a62..f90c522 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -84,6 +84,7 @@
     [grpc-testing:jenkins_test_results.aggregate_results]
   WHERE
     timestamp >= DATE_ADD(CURRENT_DATE(), -1, "WEEK")
+    AND platform = '"""+platform_string()+"""'
     AND NOT REGEXP_MATCH(job_name, '.*portability.*') )
 GROUP BY
   filtered_test_name