Frequent bad file descriptor errors on iOS

We deploy a Flutter app and have been noticing frequent exceptions from our HTTP requests:

```
SocketException: OS Error: Bad file descriptor, errno = 9, address = , port = 64436
```

From my discussion with @johnfesa, it is sometimes expected for iOS to throw these bad file descriptor errors. See Apple's [Networking and Multitasking](https://developer.apple.com/library/archive/technotes/tn2277/_index.html#//apple_ref/doc/uid/DTS40010841-CH1-SUBSECTION3) documentation. However, we're filing this issue for a few reasons:

- Since this exception is expected to occur on iOS, we were wondering if it might be a good idea to raise a more specific exception than a generic OS error.

- We're noticing this error frequently enough that we wanted to double check that there isn't an issue with the way the sockets are being managed that would be causing it.