Android: make use of globSelectors in instrumented tests

Our implementation hasn't evolved from the first two days and it runs all of the tests.

We can make use of glob selectors 

```scala
globSelectors: Task[Seq[String]]
```

and the adb Activity Manager (am) [options](https://developer.android.com/studio/test/command-line#am-instrument-options) to allow users to select classes and methods to run

cc: @souvlakias 