Introduce ignition state property in VHAL

Bug: b/32312972

Test: added tests in Car Service (another CL), also this property
      should be veirified in VTS
Change-Id: I3531227f2f12806a67926cfd930547df54475991
diff --git a/vehicle/2.0/default/impl/DefaultVehicleHal.cpp b/vehicle/2.0/default/impl/DefaultVehicleHal.cpp
index 4e27bdc..6cbcfe3 100644
--- a/vehicle/2.0/default/impl/DefaultVehicleHal.cpp
+++ b/vehicle/2.0/default/impl/DefaultVehicleHal.cpp
@@ -87,6 +87,9 @@
         case VehicleProperty::DRIVING_STATUS:
             v = pool.obtainInt32(toInt(VehicleDrivingStatus::UNRESTRICTED));
             break;
+        case VehicleProperty::IGNITION_STATE:
+            v = pool.obtainInt32(toInt(VehicleIgnitionState::ACC));
+            break;
         default:
             *outStatus = StatusCode::INVALID_ARG;
     }