How to add woocommerce products header title in woocommerce_breadcrumb hook to function.php

I am supprised that this question still accepts answers once woocommerce is a plugin and out of the scope of this chat.
Anyhow for what I have understood you want to show the product title on the woocommerce breadcrumb, Woocommerce breadcrumb already does that by default, there is no need of any changes, just remove your code.

woocommerce_breadcrumb();

If you really want to add to you function the product tittle, you can call it like this

global $product;
echo $product->name;

However this will only works on the product page, on the shop page and like so will not show the product name, or will only show the first product name.