[BUG] [Angular Client]Pattern still fall back to en-US even though defaultLocale is set as NOT en-US locale.

Describe the bug
Pattern still fall back to en-US even though defaultLocale is set as NOT en-US locale.

To Reproduce
Steps to reproduce the behavior:

1. Set default locale in your app with below:
   localeService.setDefaultLocale({
   languageCode: 'ja',
   languageName: 'Japanese',
   regionCode: 'JP',
   regionName: 'Japan'
   })
2. Adding ja pattern file(locale_ja.ts) to scr/data directory.
3. Requesting the ja-JP translation and pattern.

Expected behavior
Can get ja_JP pattern from local stored file(locale_ja.ts).