This is a pretty awkward sentence, which I think is because it is trying to do too many things. I think it would make more sense here to use multiple strings such as:-

 - "Request to become a translator for locale '#{sendEmail.locale.localeId.id}'"
 - "Request to become a reviewer for locale '#{sendEmail.locale.localeId.id}'"
 - "Request to become a coordinator for the '#{sendEmail.locale.localeId.id}' language team"

Superficially it looks like there is duplication, but the sentence structure might be different between each of these strings for some languages so I think they make more sense to be separated.