Let's also add a `default_name` for this substitution:  ```  ...      register_expansion 'Canvas.term.name', [],                          -> { @context.enrollment_term.name },                          TERM_NAME_GUARD,                           default_name: 'canvas_term_name'  ...  ```  This will allow us to use this variable expansion with LTI 2.x tools in an easier way as well.