[Enrollment V2] Fix user key-pair metric

Fix a typo that incorrectly logs the user key-pair state on CryptAuth
v2 Enrollment manager startup. Add unit tests to cover the possible v1
and v2 starting user key-pair states.

Bug: 899080
Change-Id: Ie48cf9fb0946bf38dcd68c17cc3c286767f856dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1622386
Auto-Submit: Josh Nohle <nohle@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Josh Nohle <nohle@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661896}
2 files changed