add_filter( 'gform_field_content', function ( $field_content, $field ) {
    if ( $field->type == 'creditcard' ) {
        $field_content = str_replace( ".1' id", ".1' autocomplete='cc-number' id", $field_content );
        $field_content = str_replace( "_2_month'", "_2_month' autocomplete='cc-exp-month'", $field_content );
        $field_content = str_replace( "_2_year'", "_2_year' autocomplete='cc-exp-year'", $field_content );
        $field_content = str_replace( ".3' id", ".3' autocomplete='cc-csc' id", $field_content );
        $field_content = str_replace( ".5' id", ".5' autocomplete='cc-name' id", $field_content );
    }

    return $field_content;
}, 10, 2 );