[INTERNAL] sap.m.MessagePopoverItem - setter code made more clear
[INTERNAL] sap.m.MessagePopoverItem - setter code made more clear

Change-Id: Iec0ef82d6448de2c5d68daf193b3b2b018cca7a2

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