Convert Gravity Form multiselects to ACF format

gform_acf.php

<?php

add_action('gform_after_submission_14', 'reformat_multiselect', 10, 2);
function reformat_multiselect($entry, $form) {

	$post_id = $entry['post_id'];
	$selects = array(
		'custom_field1' => 'ACF_field_key',
		'custom_field2' => 'ACF_field_key',
		'custom_field3' => 'ACF_field_key'
	);

	foreach ($selects as $name => $key) {
		$custom = get_post_meta( $post_id, $name, false );
		delete_post_meta( $post_id, $name );

		$value = maybe_serialize($custom);

		if (function_exists('update_field'))
			update_field($key,$value,$post_id);
		else
			add_post_meta($post_id,$key,$value);
	}

}