Simulating input for Unity Gear VR application.

I just bought a Samsung S6 device for development purposes and wonder if there is a way to simulate input for Unity 5 GearVR application without having a GearVR ('Virtual Reality Supported' build option is on)?

I know there is an option of buying a game controller which will generate the corresponding input which is fine for my purposes. However I'd like to know if there is any software way to send input before buying another device.

So far "adb shell input..." command is probably what I was looking for but unfortunately the app doesn't react when I'm sending left/right signal:

adb shell input gamepad keyevent 21 0 (maybe I'm doing it in a wrong way?)

Ideally it would be great if there is a way for VR app to get input from device's orientation sensor. But just a command to rotate/shift a scene a little bit is fine.

Thanks!