platform2: Remove legacy inherit-review-settings-ok files.

BUG=None
TEST=Trybot run on paladin, release, and chromiumos-sdk builders.

Change-Id: I11a13e64cd1fd9e3394d1f298425d29204bb06aa
Reviewed-on: https://chromium-review.googlesource.com/212840


Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>