Only this worked for me for ACF 5.4
function my_acf_admin_head() {
?>
<script type="text/javascript">
(function($){
$(document).ready(function(){
$('.layout').addClass('-collapsed');
$('.acf-postbox').addClass('closed');
});
})(jQuery);
</script>
<?php
}
add_action('acf/input/admin_head', 'my_acf_admin_head');