SAML Attribute value that contains a child element

For a SAML SSO I need to configure a BIG-IP IDP that will send the following SAML attribute:

 

 

I tried to insert the attibute value with use of a Variable Assign agent in the VPE, like this:

 

 

But, the BIG-IP seems to translate the 'greater-than' and 'less-than' characters to entity references (see example below). This causes the SP not to understand the SAML request.

 

 

Anyone else ran into this? Is there an easy fix?