Wearing a shelf mushroom hides the helmet layer of the player's skin

Steps to reproduce

• In the character creator, equip a headwear item

• Enter a world and equip a shelf mushroom in the head slot with the following command:
  replaceitem entity @s slot.armor.head 0 shelf_mushroom

Observed results

• The shelf mushroom is correctly visible on the front of the player’s head.

• However, the helmet layer of the skin is no longer visible like when a carved pumpkin is worn.

Expected results

• Shelf mushrooms should not hide the helmet layer as they do not encompass the player's head.