Request: Add an espresso sample with multiple modules in 1 app

If someone wants to add instant app support to their app or just divide their app into separate modules, it would be nice to be able to test those modules using Espresso.
I couldn't find any examples that show the use of Espresso with multiple modules in 1 app.

Can someone add this?

Start by reviewing the existing Espresso examples and the repository structure to understand how samples are organized. Add an app sample that contains multiple modules and demonstrates testing those modules with Espresso; done means the sample builds and clearly shows the requested setup.

Written by the indexing model from the issue text.