Pass in correct backend id into data load from runtime (#4218)

Summary:
Pull Request resolved: https://github.com/pytorch/executorch/pull/4218

The runtime now passes in the backend id into the SegmentInfo for its load() call.

Diff stack:
- (  ) [[1/n][executorch] Introduce new DataLoader::load() with segment info](https://www.internalfb.com/diff/D59399538?dst_version_fbid=2979141262226992)
- (  ) [[2/n][executorch] Switch to DataLoader::load in runtime](https://www.internalfb.com/diff/D59594142)
- (**x**) [[3/n][executorch] Pass in correct backend id into data load from runtime](https://www.internalfb.com/diff/D59606243)

Reviewed By: dbort

Differential Revision: D59606243

fbshipit-source-id: b4af5e1bb2e53f576ab75a65d2ef950cc051e8c9