Ford Focus MK2 Reverse and PRK SW wiring for head unit

Hello!

I've installed a Kenwood DMX8019-DABS a while ago and everything works exceptionally well. But recently I've stumbled upon a minor issue. I use CarPlay on the head unit and it works perfectly. But when I try to plug in an Android device to try out Android Auto I get a message on the phone saying that I should pull on the parking break. Doing so, does absolutely nothing. 1-2 minutes of reading online, and the issue is that I didn't wire up the parking sensor wire. 

Aside from the parking sensor wire, the head unit also has Speed Pulse input and Reverse sensor wire. 

My question is where should I connect these three wires? I guess reverse is used for the reverse camera and since I don't have one it might be useless (only if it turns the volume down when in reverse, in which case I would like to connect it). The Speed Pulse input, I guess, is used for dynamic volume, and the park break sensor for cases that need confirmation that the car is parked.

When looking for a solution for Android Auto I saw that the fastest way is to connect the parking sensor wire to ground, that way it's always on.

This is the manual entry for the accessory wires. 

Does anyone have any idea where should I connect these three wires correctly? 

Also, as a secondary question, is there any way of using the Kenwood head unit with the car completely off? I was able with the stock head unit, but on this one, I have to at least turn on the accessories to be able to turn the screen on.

Thank you very much.