Mobile browsers are adding .html to filename on download

PHP Snippet 1:

header('Content-Description: Download vCard');
header('Content-Type: text/vcard');
header('Content-Disposition: attachment; filename='.$your_filename_here);
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
ob_clean();
flush();
echo $vcard_serialized; //echo the content
exit;