[MC-279421] Shulker Box drops the items that were inside it when it breaks.

Shulker Box drops the items that were inside it when it breaks.

What I expected to happen was...:
I was expecting to break my shulker with my items in it.

What actually happened was...:

The Shulker box was broken but all the items were on the ground like when you break a chest with things in it.

Steps to Reproduce:
1. Craft a shulker box and put it on the ground
2. Put things inside the shulker box
3. Break the shulker box