Slice Children reverts back after saving overrides 

**Describe the bug**
When I change the order of child entities in a slice, and save the override, the order reverts back

**Steps to reproduce**
Create an entity, add two child entities. 
Create a slice with the parent entity.
Change the order of the Children entity.
Save Overrides

**Expected behavior**
The Children  entity order does not revert.


**Lumberyard version**
1.27


