Description
Related to #10736
When opening the aggregations drop-down and its near the bottom of the screen, the drop-down shows below the item so it's not fully visible. Second time you open it, it opens above the target element so it's visible.
- igniteui-angular version:
- browser:
Steps to reproduce
- Open the pivot grid dev sample.
- Open one of the values aggregation drop-downs.

Result
It opens below the target, where there's not enough space, so it's not fully visible.
Expected result
Should open above the element so it's visible.
Attachments
Attach a sample if available, and screenshots, if applicable.