code: public VehicleInterfaceDescriptor getActiveVehicleInterface() {
          VehicleInterfaceDescriptor descriptor = null;
          if(mRemoteService != null) {
              try {
                  descriptor = mRemoteService.getVehicleInterfaceDescriptor();
              } catch(RemoteException e) {
                  Log.w(TAG, "Unable to retrieve VI descriptor", e);
              }
  
          }
          return descriptor;
      }
docs: Returns a descriptor of the active vehicle interface.
  
  @return A VehicleInterfaceDescriptor for the active VI or null if none is
  enabled.