[INTERNAL] sap.m.Popover: show scrollbar when overflowing
[INTERNAL] sap.m.Popover: show scrollbar when overflowing

This issue was found in visual test

Change-Id: I20f256c550f6dcfd3e55ab9c675aaad95da28858

cschuff/openui5,SAP/openui5,cschuff/openui5,SAP/openui5,cschuff/openui5,SAP/openui5,SAP/openui5