Show more detailed download progress upload for system updates

[AntsyBoi]

When expanding the "Downloading system update" notification it should show more detailed info about the download progress like how much it has already downloaded (in megabytes) and how big the update is in total and then a percentage for how much is downloaded. Less useful ones would be showing download speed and maybe an ETA, but just having the how much downloaded and how much total would be a very nice addition.

A percentage for verification of system update progress would also be a good addition.