v1.0.0: Add youtube video parsing

* Add saving `youtube` mode to `app_reporting_pack.yaml`
* Document using the `youtube` mode of fetching video orientation
* Add option of specifying how to save the config
* Add `--generate-config-only` to stop script execution when config is
  generated

Change-Id: I6fd672d46422d9e0e7c8bf891eecaf5b192b5a84