GitLab

Add ToLocalizedString() function to WeeklyTime for later
use in the UI for DeviceAutoUpdateTimeRestrictions.

BUG=chromium:852860
TEST=unit tests

Change-Id: I85db9b19a3f1a1b589c26c064c221fe8e2137123
Reviewed-on: https://chromium-review.googlesource.com/1119392
Commit-Queue: Adolfo Higueros <adokar@google.com>
Reviewed-by: Pavol Marko <pmarko@chromium.org>
Reviewed-by: Sergey Poromov <poromov@chromium.org>
Reviewed-by: May Lippert <maybelle@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574207}