[Eche] Disable syncing device attestation certificates with Cryptauth.

Original change's description:
> Revert "Reland: "[Eche] Default-enable attestation cert generation.""
>
> This reverts commit 45aa4f938879fc380693a7ad00cec9f0bb72bd36.
>
> Reason for revert: This change will dramatically spike Google server traffic if it lands in stable-channel. Please see b/254536039 for full details.
>
> Original change's description:
> > Reland: "[Eche] Default-enable attestation cert generation."
> >
> > This is a reland of crrev.com/c/3896891.
> >
> > crrev.com/c/3896891 caused the following crash: https://paste.googleplex.com/6334225086152704. This crash occurs when logging in a new user, because crrev.com/c/3896891 did not
> > appropriately adjust
> > //ash/services/device_sync/public/cpp/device_sync_prefs.cc.
> > This reland addresses that.
> >
> > TEST: Same tests as previous CL and verified the reland fix by
> > logging in a new user and confirming no crash occurs.
> >
> > Bug: 246842111
> > Change-Id: I3d9b518b16a1f71d2d91e3467c0d6539ec5658d9
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3900673
> > Reviewed-by: Jon Mann <jonmann@chromium.org>
> > Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
> > Cr-Commit-Position: refs/heads/main@{#1047790}
>
> Bug: 246842111
> Change-Id: I353f492e226f725f1d38eda5efea89ec9790bae8
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3965546
> Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
> Reviewed-by: Jon Mann <jonmann@google.com>
> Cr-Commit-Position: refs/heads/main@{#1061660}

Bug: b/240239595
Change-Id: I2b33e4c36b2ae6ebfcd2e205353ef7df9fefeca7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4021339
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Auto-Submit: Jon Mann <jonmann@chromium.org>
Commit-Queue: Jon Mann <jonmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1085596}