function _onConditionPropagation(sReason, oConfig) {
		const oDelegate = this.bDelegateInitialized && this.getControlDelegate();
		if (oDelegate) {
			oDelegate.onConditionPropagation(this, sReason, oConfig || this.getProperty("_config"));
		}
	}
Determines the icon for the value help.

@returns {null|string} Name of the icon. If <code>null</code> no value help icon will be shown and it is used only as typeahead.

@private
@ui5-restricted sap.ui.mdc.field.FieldBase