Add backorder product message above the estimated delivery text

functions.php

add_filter( 'xa_estimated_delivery_cart_checkout_page_html_formatted_date', 'ph_estimated_delivery_modify_cart_checkout_page_html',11,2 );
function ph_estimated_delivery_modify_cart_checkout_page_html( $text, $test  ) {
	global $woocommerce;
    $items = $woocommerce->cart->get_cart();
	$count=0;
    foreach($items as $item => $values) { 
		$product_id=(wp_get_post_parent_id($values['data']->get_id())==0) ? $values['data']->get_id() : wp_get_post_parent_id($values['data']->get_id());
    	if($values['data']->get_stock_status()=='onbackorder')
    	{
    		$count++;
    		break;
    	}
    }
    if($count > 0)
    {
    	$back_order_text='<tr class="shipping"><th>Your cart having back-order products</th></tr>';   // add your message here
   		$text=$back_order_text.$text;
    }
    return $text;
}