Bug 1597573 - Add trs to availableLocaleDisplayNames in mozIntl.jsm r=Pike

Differential Revision: https://phabricator.services.mozilla.com/D53781

--HG--
extra : moz-landing-system : lando

toolkit/components/mozintl/mozIntl.jsm

@@ -635,6 +635,7 @@ const availableLocaleDisplayNames = {
     "tn",
     "to",
     "tr",
+    "trs",
     "ts",
     "tt",
     "tw",