summoned_entity advancement trigger doesn't work for villager_golem

If you use the summoned_entity trigger in an advancement, and you specify the type as villager_golem, then summoning an iron golem does not grant the advancement as it should.

To test:

1. Use the attached root.json advancement file in your data/advancements folder (give it any name you like).

2. Go into your world and build an iron golem.

Expected: I'd expect the advancement to be granted and visible after building the golem.

Actual results: It's not visible in the tree, and if you run /advancements test for it, it says it was never granted.