Update to work the same as javascript version
Update to work the same as javascript version

The google/libphonenumber javascript version has been updated such that it can both take lowercase/uppercase strings and also ensure that numeric regionCodes are not counted as valid.

See https://github.com/google/libphonenumber/blob/master/javascript/i18n/phonenumbers/phonenumberutil.js#L1658

giggsey/libphonenumber-for-php