tools:locale="en" not removed in translated file

[royerdavid]

The plugin should use a country language as a generic language when the generic language doesn't exist.

Example:
"fr-CA" without "fr" should be exported as "fr"

[bretdabaker]

Thanks for reporting the bug, the tools:locale attribute should only be used for files under /values folder as described here, our backend engineers will look into it.