Smart Lock: Remove unused promo notification code.

R=hansberry@chromium.org

Bug: 899324
Test: none
Change-Id: I762ae359249c60481ba4866703aa1e7fbbc6552e
Reviewed-on: https://chromium-review.googlesource.com/c/1302330
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: James Hawkins <jhawkins@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603234}
7 files changed