[] sap.ui.table.Table - header row height is incorrect
[] sap.ui.table.Table - header row height is incorrect

- header row height was calculated based in the first cell only

Change-Id: If5be2a7335ea7a0b17891a1f51c9bbe590e8f874
BCP: 002075129500002357832016

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