add preventDefault on aggregation drop to prevent firefox open new tab when drag from palette
add preventDefault on aggregation drop to prevent firefox open new tab when drag from palette

Change-Id: I4d6ecbf73348a7f8c833a4a6fb4e979b88b1c6fa

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