[INTERNAL] sap.m.ComboBoxTextField: Code clean-up
[INTERNAL] sap.m.ComboBoxTextField: Code clean-up

Change-Id: I98acc4098e0d4347b4294eba04a556614a9e0b1d
JIRA: BGSOFUIRILA-2901

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