Chrome: 69.0.3480.0 Canary

Steps to repro:
# Enable ChromeVox with alt+ctrl+z
# Press alt+shift+s to move to the status tray
# Tab to the do not disturb switch
# Notice ChromeVox announces 'Notifications not pressed'

Expected: ChromeVox should inform the user what this switch does

Actual: I thought the switch was to turn on and off notifications and that notifications were currently off.