When pressing the leftShoulder button on a DualShock 3 controller on OSX, the TouchpadButton is also triggered, even it doesn't exist on Dualshock 3 at all.

Repro:
1. Download package and project at: https://github.com/Unity-Technologies/InputSystem
2. Use project Input Test ( Assets -> QA -> Input_Test -> Scenes)
3. Enter Playmode and switch to Dualshock test
4. Press the left shoulder button

Actual: Pressing leftShoulder button also triggers touchpad button.