[BUG] [Java Service]"null (Unknown Script)" is shown as displayName for invalid locale "12-Abcd-AA-AAAA".

Describe the bug
commit: c7afc3bee93563af3c7073adfdd5cbd9b584ca0e
"null (Unknown Script)" is shown as displayName for invalid locale "12-Abcd-AA-AAAA".

To Reproduce
Steps to reproduce the behavior:

1. Put a json file with name: messages_12-Abcd-AA-AAAA.json in VMwareVIPLocale&1.0.0 bundles.
2. Request its displayname with "http://serviceip:8091/i18n/api/v2/locale/supportedLanguageList?displayLanguage=en&productName=VMwareVIPLocale&version=1.0.0"

{
        "languageTag": "12-Abcd-AA-AAAA",
        "displayName": "null (Unknown Script)",
        "displayName_sentenceBeginning": "Null (Unknown Script)",
        "displayName_uiListOrMenu": "null (Unknown Script)",
        "displayName_standalone": "null (Unknown Script)"
      }

Expected behavior
Unknown language (Unknown Script, Unknown Region)