[MC-114105] Cleaning leather armor and shulker boxes in Creative lowers cauldron water level and modifies item

The bug

Cleaning leather armor and shulker boxes using a cauldron in Creative behaves like it does in Survival: The water level of the cauldron is lowered and the item is replaced.

Expected behavior

The expected behavior is that it acts like banners: Right clicking a cauldron only gives the player a new cleaned item (see MC-114104), and everything else remains unchanged.

How to reproduce

Change your gamemode to Creative
```
/gamemode creative
```

Place a cauldron with water

/setblock ~1 ~ ~ water_cauldron[level=3]

Right click the cauldron with dyed leather armor
```
/give @p leather_chestplate{display:{color:0}}
```
→ The color was removed from the leather armor and the water level of the cauldron was lowered