Office 365 Excel Custom Function Streaming Function should not be always executed.

As per suggested in https://github.com/OfficeDev/office-js/issues/2220, 

our workbook already set with Office.addin.setStartupBehavior(Office.StartupBehavior.none), the related CustomFunctions/Formulas (i.e. Streaming Custom Function) should not be executed by default and should only be executed when the user "connect" the add-in manually. Same behavior of the StartupBehavior for Addin