Revert "Use the locale, not the two_letters_code for crowdin"

This reverts commit 73b9e1a2aa.

crowdin.yml

@@ -9,18 +9,18 @@
 files: [
   {
     "source": "/config/locales/en.yml",
-    "translation": "/config/locales/crowdin/%locale%.yml",
+    "translation": "/config/locales/crowdin/%two_letters_code%.yml",
   },
   {
     "source": "/config/locales/js-en.yml",
-    "translation": "/config/locales/crowdin/js-%locale%.yml",
+    "translation": "/config/locales/crowdin/js-%two_letters_code%.yml",
   },
   {
     "source": "/modules/**/config/locales/en.yml",
-    "translation": "/modules/**/config/locales/crowdin/%locale%.yml",
+    "translation": "/modules/**/config/locales/crowdin/%two_letters_code%.yml",
   },
   {
     "source": "/modules/**/config/locales/js-en.yml",
-    "translation": "/modules/**/config/locales/crowdin/js-%locale%.yml",
+    "translation": "/modules/**/config/locales/crowdin/js-%two_letters_code%.yml",
   },
 ]