Set up code coverage for Robolectric tests

[vinitamurthi]

We would like to get code coverage reports for our robolectric tests. The code coverage tool needs to be compatible with Kotlin and java, as well as work on Gradle and Bazel. Jacoco seems to be a good pathway, some useful links:

• Jacoco for Kotlin: https://kevcodez.de/posts/2018-08-19-test-coverage-in-kotlin-with-jacoco/
• Jacoco in Bazel: https://github.com/bazelbuild/bazel/tree/master/third_party/java/jacoco

[vinitamurthi]

CC @BenHenning @anandwana001 , let me know your thoughts on using Jacoco! Here's the link: https://www.jacoco.org/jacoco/trunk/index.html

[BenHenning]

FYI I found out that Bazel's android local tests do not support code coverage at all, and this is something we'll need to contribute directly.

[MaskedCarrot]

May I work on this?

[peculiaruc]

Thanks for showing interest to work on this task but it already assigned.