{firefox,chromium}: accept regional languages as well to not fallback to Russian?

etc/firefox/policies/policies.json

@@ -362,7 +362,7 @@
       "intl.accept_languages": {
         "Status": "locked",
         "Type": "string",
-        "Value": "fi, en, ru"
+        "Value": "fi, fi-FI, en, en-FI, en-EU, en-IE, en-US, ru, ru-RU"
       },
       "javascript.use_us_english_locale": {
         "Comment": "Preference not allowed for stability reasons. :(",

etc/opt/chromium/policies/managed/languages.json

@@ -1,3 +1,13 @@
 {
-  "ForcedLanguages": ["fi", "en", "ru"]
+  "ForcedLanguages": [
+    "fi",
+    "fi-FI",
+    "en",
+    "en-FI",
+    "en-EU",
+    "en-IE",
+    "en-US",
+    "ru",
+    "ru-RU"
+  ]
 }