DropContainer height calculation updated to handle edge cases (#3045)
DropContainer height calculation updated to handle edge cases (#3045)

* changed the logic for container height calculation in different scenarios

* tests updated

* Fix edge case to flip the menu or select control

* updated visible area threshold to 20%

* percentVisibleAreaBelow threshold name updated with comments

HewlettPackard/grommet,HewlettPackard/grommet,HewlettPackard/grommet,grommet/grommet,grommet/grommet,grommet/grommet