Flagging a few census tests as flaky.
diff --git a/build.json b/build.json
index 8838d3a..ff992b9 100644
--- a/build.json
+++ b/build.json
@@ -810,6 +810,7 @@
     },
     {
       "name": "census_statistics_multiple_writers_test",
+      "flaky": true,
       "build": "test",
       "language": "c",
       "src": [
@@ -824,6 +825,7 @@
     },
     {
       "name": "census_statistics_performance_test",
+      "flaky": true,
       "build": "test",
       "language": "c",
       "src": [
@@ -838,6 +840,7 @@
     },
     {
       "name": "census_statistics_quick_test",
+      "flaky": true,
       "build": "test",
       "language": "c",
       "src": [