As for me, it makes sense to add coverage data (using https://codecov.io) to the Github repository. For example, openmrs-core already has one and it helps.
The benefits of adding Codecov to the Android Client on Github:
- It will help to keep track of code coverage with every pull request.
- Everyone, who hasn't even cloned the repository, will be able to see current code coverage. It can potentially encourage testers to participate in the project as the current percentage is quite low.
- Codecov can also encourage current contributors to write tests right when they add some new code, so it doesn't break the statistics.
- Everybody will be aware of current code coverage. You won't necessarily need to run any tool in Android Studio to know it.