Arrow icons for expanding items in Locals and Expressions view disappear when stepping

1. Stop at a breakpoint.
   Locals and Expressions view displays variables. If values can be expanded (e.g. arrays), it displays an arrow icon next to them:
   
2. Step forward.
   The arrows disappear:
   
3. Click where an arrow was displayed.
   The value will be expanded.

When a value can be expanded, Creator should always indicate this. It should always display the arrows.