Saving and re-opening a v2 array does not report (or save) correct memory order

```python
import zarr
import zarr.storage

store = zarr.storage.MemoryStore()
arr = zarr.create((100,), store=store, path="a", zarr_format=2, order="F")
print(arr.order)
# "F"

arr = zarr.open(store, path="a")
print(arr.order)
# "C"
```

I would expect the memory order to be persisted and the same when I re-open the array.