Android ADB - how to generate or retrieve reports from instrument from commandline?

I would like to run my Android tests on emulators and on devices from command line. That is easily achievable with a command line like:

adb shell am instrument -w package/runner

I would like to retrieve the reports that the gradle plugin generates without having the source for the apks. So, I can't simply implement some listener interface. All I have are the APKs and I know the package/runner.

Is there a way to pass some -e argument to InstrumentationTestRunner to define a folder where I can get the reports? Does it generate the reports in the device somewhere in /data/data?

Thanks in advance!