New measures to understand Windows Update success

To better understand health of driver installations, we have developed two new measures that provide a view into the health of drivers using Windows Update (WU).

1. Percent of machines that WU reported a successful download within the last 28 days (https://docs.microsoft.com/en-us/windows-hardware/drivers/dashboard/pct-machines-wu-success-download) looks at the pre-install period of a driver to ensure there isn't an issue downloading the driver from WU
2. Percent of machines that WU reported a successful installation within the last 28 days (https://docs.microsoft.com/en-us/windows-hardware/drivers/dashboard/pct-machines-wu-success-install) looks at whether WU reported a successful installation.

These measures are currently being evaluated and will be used to make accept/reject decisions starting April 13, 2020.