[INTERNAL] sap.m.StepInput: Minor test fix
[INTERNAL] sap.m.StepInput: Minor test fix

Change-Id: I11604a5bc1ed9e2ebca01168ada50e4e2377f36e
BCP: N/A

SAP/openui5,cschuff/openui5,SAP/openui5,SAP/openui5,cschuff/openui5,SAP/openui5,cschuff/openui5