[INTERNAL] sap.m.ComboBox: improve dropdown list vertical placement
[INTERNAL] sap.m.ComboBox: improve dropdown list vertical placement

BCP: 1670099989

Change-Id: Ic84331bb2cd6856f681e74d711403cb431b0f377

SAP/openui5,SAP/openui5,nzamani/openui5,cschuff/openui5,SAP/openui5,nzamani/openui5,olirogers/openui5,nzamani/openui5,SQCLabs/openui5,SAP/openui5,olirogers/openui5,SQCLabs/openui5,olirogers/openui5,cschuff/openui5,SQCLabs/openui5,cschuff/openui5