使用ViewModel和LiveData来解决该问题。在Activity或Fragment中创建ViewModel并使用LiveData来观察数据的变化。这样即使屏幕旋转或者配置变化导致Activity或Fragment重新创建，ViewModel也会持有旧有的数据并且LiveData仍可以接收到从Firestore返回的新数据。

示例代码如下：

1. 创建ViewModel类

public class MyViewModel extends ViewModel {
    private final LiveData> myDataList;
    private final MyRepository myRepository = new MyRepository();

    public MyViewModel() {
        myDataList = myRepository.getMyDataList();
    }

    public LiveData> getMyDataList() {
        return myDataList;
    }
}

2. 在Repository中实现Firestore实时监听器

public class MyRepository {
    private final MutableLiveData> myDataList = new MutableLiveData<>();

    public MyRepository() {
        FirebaseFirestore.getInstance().collection("myCollection")
                .addSnapshotListener((queryDocumentSnapshots, e) -> {
                    if (e != null) {
                        Log.e(TAG, "Firestore listener failed", e);
                        return;
                    }

                    List dataList = new ArrayList<>();
                    for (QueryDocumentSnapshot documentSnapshot : queryDocumentSnapshots) {
                        dataList.add(documentSnapshot.toObject(MyData.class));
                    }

                    myDataList.postValue(dataList);
                });
    }

    public LiveData> getMyDataList() {
        return myDataList;
    }
}

3. 在Activity或Fragment中使用ViewModel和LiveData

public class MyActivity extends AppCompatActivity {
    private MyViewModel viewModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_my);

        viewModel = new ViewModelProvider(this).get(MyViewModel.class);
        viewModel.getMyDataList().observe(this, myDataList -> {
            // 处理数据变化
        });
    }
}