After its initial, human-based touchscreen stress testing saw the iPhone besting three rival Android handsets—the HTC Droid Eris, the Motorola Droid, and the HTC-built Google Nexus One—the MOTO Development Group has performed another set of tests using a laboratory robot to remove any inconsistencies caused by human error. The new tests again found that the iPhone bests its rivals in both “medium” and “very light”…