Fix MetricsReporting - pass correct config to ReportingFactory
Created by: davemevans
https://github.com/Dash-Industry-Forum/dash.js/pull/2154 (specifically https://github.com/Dash-Industry-Forum/dash.js/commit/e6a1a4ffa6fd55f0f3e44bf74aaf3bed0c632c38) broke metric reporting because it did not pass MetricsConstants to all necessary modules - ReportingFactory and the modules it creates require this config.
I also changed some let
to const
whilst there.