Bug 1734722 - Part 3: Allow domstreams: True in build r=aki

Differential Revision: https://phabricator.services.mozilla.com/D137500

taskcluster/gecko_taskgraph/transforms/test/other.py

@@ -766,6 +766,7 @@ test_setting_description_schema = Schema(
                 "ccov",
                 "clang-trunk",
                 "devedition",
+                "domstreams",
                 "lite",
                 "mingwclang",
                 "shippable",