Always set default locale on admin. Also fixes an error for invalid l… (#2306)
Always set default locale on admin. Also fixes an error for invalid l… (#2306)

* Always set default locale on admin. Also fixes an error for invalid locales coming in. Closes https://github.com/brave-intl/publishers/issues/2294
* Only switch on locale checks for get requests

brave/publishers,brave/publishers,brave/publishers