Move Emulated User HAL to Emulated Vehicle Connector Class

Test: build; manually tested the following commands
```
> adb shell lshal debug android.hardware.automotive.vehicle@2.0::IVehicle/default --user-hal
> adb shell lshal debug android.hardware.automotive.vehicle@2.0::IVehicle/default --set 299896583 a 1 i 666 i 1 i 11
```
Bug: 166706927
Change-Id: Ic5774e56dec7febcfeaf496111ba77907e1b7fac

Change-Id: Ib2545b7e0d6b2eea0734fe013451b1365ee0e8ff
Merged-In: Ib2545b7e0d6b2eea0734fe013451b1365ee0e8ff
(cherry picked from commit 87278462)