Modify list_system_health_stories to generate_system_health_csv

This CL also check in system_health_stories.csv file, which will be used to later
replace https://bit.ly/csh-stories

BUG=723636

Review-Url: https://codereview.chromium.org/2888133002
Cr-Commit-Position: refs/heads/master@{#473213}
11 files changed