Zombie's Armor cannot be set to 0

Summary

I wrote the code to set Zombie's armor to 0, but Zombie's armor is set to 2 set in Minecraft When the armor is set to 1, it seems to work well, so it seems to be a problem when the armor is set to 0

Steps to reproduce

Zombie:
  Type: ZOMBIE
  Health: 1200
  Armor: 0

Current behavior

I can't make a zombie with 0 armor

Intended correct behavior

If I set armor to 0 in code, zombies with armor set to 0 should come out

Proposed fixes

There seems to be no code running to set the armor to 0 because the code was written assuming that all entities in Minecraft have 0 armor