Fixed screenshot for android

This fixed screenshot for me. There were several issues - the adb command wasnt returning a screenshot - i broke this into two commands - create screenshot in shell and another for copying it locally. Then when this was fixed, it still seemed to be throwing a 500 even though the screenshot was coming back in the REST GET request, so I reverted the previous change to return a success code, because it didnt appear to be evaluating correctly. I did not identify how to fix this to evaluate and return an appropriate code, so probably always returns success here,as it did before.