- Update the three `HttpDataSource` implementations to use the
Content-Range response header to determine when this is the
case. The Content-Range header is included when the status
code is 416. See [here](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/416).
- Update `ByteArrayDataSource` to conform to the requirement.
- Update `DataSourceContractTest` to enforce the requirement.
PiperOrigin-RevId: 363642114
