Develop a piece of code that inserts a new record in a database that is available in another application and can be accessed via the authority "hello.world.2". The new record, which is detailed below, must be saved in a table named 'cars'. 'maker':'BMW' 'model':'X7' 'year':2018. Then, briefly explain the role of the 'UriMatcher' class in an application that needs to share its data with other apps.