Add test config to RetailDemoTests Details about test configs changes are tracked in doc https://docs.google.com/document/d/1EWUjJ7fjy8ge_Nk0YQbFdRp8DSHo3z6GU0R8jLgrAcw/edit# Bug: 35882476 Test: local test Change-Id: I36d3c90ca1fce72104c3ced12496c35c30002713