setLocales

The app's own languages (Android's per-app language, API 33+), as BCP-47 tags in preference order ("fr-FR", "en"); an empty list makes it follow the system again. The tags are checked and canonicalized by the server (INVALID_ARGUMENT for a malformed one) and the change is read back. Like the Device conditions, the app's languages before the session's first change come back on Device.detach. Below API 33: ServerException (FailureReason.UNSUPPORTED_API). Android applies it as a configuration change: the app's activities are recreated unless it handles the change itself.