Move CryptAuth v2 Enrollment constants to separate file

Bug: 899080
Change-Id: Ic3428f5c3c1387ca63138f20b6e52d588a9a8619
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1499835
Commit-Queue: Josh Nohle <nohle@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637533}
8 files changed