Refine unplugged electrode case

[zachtes13]

• Our handling should be more nuanced
• Initialize AED electrode plugged in value to random value
• If unplugged, status fails and will continue to do so until user reacts by pressing button below
• Add user button "Plug in Cable", which will set the cable plugged in to true
• Now, when user restarts, AED should pass (if battery conditions are met)

[zachtes13]