Gravity Form Australian Phone Number Filtering

functions.php

add_filter( 'gform_phone_formats', 'au_phone_format' );
function au_phone_format( $phone_formats ) {
    $phone_formats['au'] = array(
        'label'       => 'Australia',
        'mask'        => false,
        'regex'       => '/^\({0,1}((0|\+61)(2|4|3|7|8)){0,1}\){0,1}(\ |-){0,1}[0-9]{2}(\ |-){0,1}[0-9]{2}(\ |-){0,1}[0-9]{1}(\ |-){0,1}[0-9]{3}$/',
        'instruction' => false,
    );
 
    return $phone_formats;
}