MDT 2013 update 2 UDI wizard - domain join credentials issue

Hi,  I recently upgraded to MDT Update 2 running SCCM 1602.  Previously I used to install windows 7 using MDT UDI (2013 I think?) and configuring the OSDJoinDomain and OSDJoinPassword variables as collection variables on the collections I had the task sequence.  They would show up like the below.



This is what I get in MDT Update 2



This is the same issue discussed in the below forum for MDT 2013 Update 1 and they only found a workaround which was to create task sequence variables which for some reason isn't work in Update 2 or I'm missing something.  I would prefer to use collection variables as it prevents them from being stored in clear text. 

https://social.technet.microsoft.com/Forums/en-US/c4dcc029-0561-4d4e-9659-b5271078a8f0/mdt-2013-update-1-udi-wizard-domain-join-credentials-issue?forum=configmanagerosd