[INTERNAL][FIX] sap.m.SelectDialog: Dissapearing SearchField
[INTERNAL][FIX] sap.m.SelectDialog: Dissapearing SearchField

If the SelectDialog is binded with data and the busy indicator
is on, the whole header was hidden thus leaving transparent part
of the SelectDialog uncovered. We now just disable the search
field before the data is loaded and once this is done - we enable it
again.

Change-Id: I9904eb0041e02b8438bc9923087b11b9a0047a9d

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