Viewmodel构造函数添加变量

viewModel构造函数中添加变量，使用方法：

viewModel = ViewModelProviders.of(this, object : ViewModelProvider.Factory{
          override fun <T : ViewModel?> create(modelClass: Class<T>): T {
              if (modelClass.isAssignableFrom(XXViewModel::class.java)) {
                  return XXViewModel(XX)  as T
              }
              throw  IllegalArgumentException(" unKnown ViewModel class ")
          }
      }).get(XXViewModel::class.java)