Add "Infra" to the builder_name_schema

BUG=skia:4763
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2154433002

Review-Url: https://codereview.chromium.org/2154433002
diff --git a/tools/builder_name_schema.json b/tools/builder_name_schema.json
index cffe9bf..6a8c921 100644
--- a/tools/builder_name_schema.json
+++ b/tools/builder_name_schema.json
@@ -12,6 +12,9 @@
     "Housekeeper": [
       "frequency"
     ],
+    "Infra": [
+      "frequency"
+    ],
     "Build": [
       "os",
       "compiler",