arc: Dedup logic in IsArcAllowedForProfile()/UpdateEnabledStateByUserTypeUMA()

Bug: 929583
Change-Id: I36470d876baef70a60e789d9ee019c9a2eaceb36
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1504488
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Reviewed-by: Yury Khmel <khmel@chromium.org>
Commit-Queue: Shao-Chuan Lee <shaochuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#639386}
3 files changed