[DeviceSync v2] Add CryptAuthDevice class

The CryptAuthDevice class holds information for a device managed by
CryptAuth and sent to clients in v2 DeviceSync's SyncMetadataResponse.
This class is analogous to CryptAuthKey used for v2 Enrollment.

Bug: 951969
Change-Id: Icc9b7aefa8649a30f6fc301f336b3f2c778c6670
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1615705
Commit-Queue: Josh Nohle <nohle@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661925}
6 files changed