[FIX] m.DatePicker: OnChange compares previous and old value correctly
[FIX] m.DatePicker: OnChange compares previous and old value correctly

Change-Id: I36d851fd248a827617a66552d4a800c887b2f3df
BCP: 1670542205

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