Alarm not stopping notif

[thdelmas]

Bug Description

When the alarm is triggered it appears full screen with the slide to turn off
However if the user clicks first on the notification another activity opens on top of the first one
When the user will slide to shut down it will turn off only one of the activity leaving the user on the device launcher without any way to turn off the alarm

What's expected

1. Make sort of that the alarm shutdowwn doesn't depend on the activity, so where ever it's closed it applies everywhere
2. Make sort of that the app doesn't open twice the same activty unless necessary