[roll] Roll fuchsia Reland "[pkg] Only use BlobReader/BlobWriter to access blobs."

This reverts commit 2a7d40c8f2885fda3dc60792a5d282037b6a5a46.

Reason for revert: https://fuchsia-review.googlesource.com/c/fuchsia/+/1250905 to fix the race.

Original change's description:
> Revert "[pkg] Only use BlobReader/BlobWriter to access blobs."
>
> This reverts commit b038e56fc7f1126c402cae12589b8796101cbe9a.
>
> Reason for revert: b/409611771
>
> MULTIPLY: fuchsia-pkg://fuchsia.com/pkg-resolver-integration-tests#meta/resolve-resumes-blob-gets.cm
>
> Original change's description:
> > [pkg] Only use BlobReader/BlobWriter to access blobs.
> >
> > Removes the conditional use in pkg-cache main for choosing between using
> > the old fuchsia.io protocols and the new reader/writer protocols.
> >
> > Cleans up all the production uses of blob opening with fuchsia.io, and
> > updates all the integration tests that relied on pkg-cache behaving this
> > way.
> >
> > Does not clean up all the optionals and branches for the number of
> > hermetic tests that explicitly call the fuchsia.io paths or create mocks
> > assuming that the fuchsia.io paths are available.
> >
> > Original-Bug: 408439508
> >
> > Change-Id: Ifc3dc87811dff5a78c97ae76f9f81b39c8b8aee5
> > Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1243164
> > Reviewed-by: Mark Dittmer <markdittmer@google.com>
> > Commit-Queue: Martin Lindsay <mlindsay@google.com>
> > Reviewed-by: Ben Keller <galbanum@google.com>
>
> Original-Bug: 408439508
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Change-Id: I9cf97eac437326266f3566175fd25e6225f487a0
> Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1249844
> Reviewed-by: RubberStamper 🤖 <android-build-ayeaye@system.gserviceaccount.com>

Original-Bug: 408439508
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1249548
Original-Revision: 2aab7805e31cb7d06119935cd9bbcec2c3bb17a0
GitOrigin-RevId: faa7453ab943c42db03989c1a2291b425ce98eab
Change-Id: I1ead3409dea7e71edc9866007eaa5ffdee732abc