Fix blueprint helper test
Fix blueprint helper test

It fixes the test when generating a helper in a MU `dummy` app.

It continues the work of #17658 that requires this change when #17689 was merged.

qaiken/ember.js,fpauser/ember.js,elwayman02/ember.js,miguelcobain/ember.js,GavinJoyce/ember.js,kellyselden/ember.js,sandstrom/ember.js,emberjs/ember.js,asakusuma/ember.js,sandstrom/ember.js,miguelcobain/ember.js,sandstrom/ember.js,elwayman02/ember.js,sly7-7/ember.js,kellyselden/ember.js,knownasilya/ember.js,elwayman02/ember.js,tildeio/ember.js,intercom/ember.js,qaiken/ember.js,GavinJoyce/ember.js,emberjs/ember.js,mixonic/ember.js,cibernox/ember.js,tildeio/ember.js,qaiken/ember.js,mixonic/ember.js,givanse/ember.js,miguelcobain/ember.js,sly7-7/ember.js,miguelcobain/ember.js,stefanpenner/ember.js,stefanpenner/ember.js,cibernox/ember.js,cibernox/ember.js,mfeckie/ember.js,mfeckie/ember.js,mixonic/ember.js,GavinJoyce/ember.js,sly7-7/ember.js,givanse/ember.js,givanse/ember.js,asakusuma/ember.js,GavinJoyce/ember.js,knownasilya/ember.js,qaiken/ember.js,intercom/ember.js,asakusuma/ember.js,fpauser/ember.js,intercom/ember.js,elwayman02/ember.js,fpauser/ember.js,fpauser/ember.js,tildeio/ember.js,cibernox/ember.js,knownasilya/ember.js,emberjs/ember.js,stefanpenner/ember.js,givanse/ember.js,intercom/ember.js,kellyselden/ember.js,mfeckie/ember.js,mfeckie/ember.js,asakusuma/ember.js,kellyselden/ember.js