[Auth-UI][v10.0.0-beta04] Phone auth error dialog ignores AuthUIStringProvider — messages always come back in English

Steps to reproduce:
1. Host PhoneAuthScreen and provide a locale-aware provider via both LocalAuthUIStringProvider and LocalTopLevelDialogController, exactly as documented in the Localization README:
DefaultAuthUIStringProvider(context, Locale.JAPAN)
2. On the enter-phone-number step, enter a malformed number and tap the send/next button.
3. Observe the ErrorRecoveryDialog shown by `dialogController.CurrentDialog()`

- `error.message` over resources for `InvalidCredentialsException, UnknownException, PhoneVerificationCooldownException, EmailAlreadyInUseException and AccountLinkingRequiredException`
it builds DefaultAuthUIStringProvider(context) with no locale, so it uses the device locale

- `values-zh-rTW` ships `fui_error_dialog_title = "Authentication Error"` and `fui_error_retry_action = "Try again"` untranslated, while `fui_email_link_dismiss_button = 「關閉」` is translated. On a zh-TW device the dialog is mixed-language even when the provider works correctly. `values-ja and values-ko` have all three.