[CrOS MultiDevice] Move CryptAuth proto definitions to DeviceSync.

CryptAuth-related files should now be part of DeviceSync in the ongoing
effort to remove the //components/cryptauth directory.

Change-Id: I287f23a85a133f5317994755946e0dd445227599
Bug: 912743
Reviewed-on: https://chromium-review.googlesource.com/c/1364303
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615283}
67 files changed