Iron Golems should grow their vines

When iron golems are spawned, they should spawn without vines and grow them over time, similarly to how copper ages. However, when discovering a village with an iron golem, there is a random amount of vines on it.

all credit to the user elitube100509 for this idea. I found this in a post titled "Random Ideas", and I thought it needed its own post, so here it is.