Reland "[webauthn] Fix reusing iCloud recovery keys"

This reverts commit f122e4a861ec856d030990c72367220b72fb7731.

There are no changes, this just has to wait for
https://crrev.com/c/5802987 to land.

The reason the Recovery test failed is that this CL exposed a bug in
the (at the time) current iteration of the test: without Vault reporting
an iCloud recovery key for the domain, the code should create a new one.
https://crrev.com/c/5802987 fixes that test bug.

Original change's description:
> Revert "[webauthn] Fix reusing iCloud recovery keys"
>
> This reverts commit df82fe10bc4af4186043807df069df233f89bdcf.
>
> Reason for revert: Failing EnclaveICloudRecoveryKeyTest.Recovery
> https://ci.chromium.org/ui/p/chromium/builders/ci/Mac13%20Tests/19058/test-results?sortby=&groupby=
> https://ci.chromium.org/ui/p/chromium/builders/ci/Mac13%20Tests/19059/test-results?sortby=&groupby=
>
> Original change's description:
> > [webauthn] Fix reusing iCloud recovery keys
> >
> > Fix a bug where two users can end up with the same recovery key.
> >
> > For now, we ignore iCloud members that belong to other security domains.
> >
> > Fixed: 360321350
> > Change-Id: Ic3cb75cdec8323606165c5f986e5f2f477513740
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5805123
> > Auto-Submit: Nina Satragno <nsatragno@chromium.org>
> > Commit-Queue: Nina Satragno <nsatragno@chromium.org>
> > Reviewed-by: Adam Langley <agl@chromium.org>
> > Cr-Commit-Position: refs/heads/main@{#1345544}
>
> Change-Id: I1ff52d64c516f063cfd73c79ee79e99006155f56
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5806428
> Owners-Override: Zonghan Xu <xzonghan@chromium.org>
> Reviewed-by: Katie Dektar <katie@chromium.org>
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Commit-Queue: Zonghan Xu <xzonghan@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1345599}

Cq-Include-Trybots: luci.chromium.try:mac12-tests
Change-Id: I2ab5c794929f154320fd05c6b340095d78db86ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5806429
Commit-Queue: Nina Satragno <nsatragno@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1347403}