[FIX] sap.m.Dialog: fix combo box button positioning issue in IE11
[FIX] sap.m.Dialog: fix combo box button positioning issue in IE11

Workaround for an IE11 layout issue, that causes a wrong positioning of
the combo box button inside the dialog control.

Change-Id: Ibdcd1f815a9ba169b9eb49f9a171a02708c52af1
BCP: 1570573944
nzamani/openui5,cschuff/openui5,SAP/openui5,SQCLabs/openui5,olirogers/openui5,cschuff/openui5,olirogers/openui5,nzamani/openui5,SAP/openui5,cschuff/openui5,olirogers/openui5,nzamani/openui5,SQCLabs/openui5,SAP/openui5,SAP/openui5,SQCLabs/openui5