add_filter( 'gform_field_value_ga_client_id', 'populate_ga_client_id' );
function populate_ga_client_id( $value ) {
    sleep(2);
	$ga_original = $_COOKIE['_ga'];
    //$ga_original = "GA1.2.225723425.1561042184";
    $ga_regex = "/(?=(^GA[0-9]+.[0-9]+.)([0-9]+.[0-9]+))/";
    preg_match_all($ga_regex, $ga_original, $ga_finalid);
    return $ga_finalid[2][0];
}