Prototyping com.android.test module and shared tests in a com.android.lib module.

[handstandsam]

Findings:

• You CAN put tests in a "com.android.library" module, include that via an app/androidTestImplementation and get it to run
• You CAN put tests in a "com.android.library" module, include that via an android-tests/implementation and get it to run
• There problem about "right clicking and running" a test that exists in a com.android.library module does exist, but this is still a huge breakthrough for sharing.
• You can just use compileOnly(project(':app')) to know about it's Activities to use from espresso, etc. That way it doesn't need to actually build that code into the final test APK.