Firmware Install Restart modal should be more verbose

## Problem

An uninformed or not so tech savvy user might be confused by the firmware update restart modal. When he installs the firmware and a restart is needed, the user has the option to restart or to cancel the restart.

What if he doesnt want to restart in that moment? He might be confused if the firmware update will still be installed later, or if nothing happened at all.

## Proposal

Add a line or description to the modal that describes the behaviour in a more verbose way.