Update dialog can't appear bug (#397)
Update dialog can't appear bug (#397)

* Update dialog can't appear bug

Problem
1. Check update as .onForeground (Siren.shared.wail(performCheck: .onForeground))
2. If user swipe down the notification center screen to the bottom of screen (by swiping downward from the very top of the device's screen)
3. And back to app can't appear update dialog

Reason
If swipe down the notification center screen to the bottom of screen
iOS call observer like this
1. starting to swipe down : willResignActiveNotification
2. reached to bottom : didBecomeActiveNotification, willResignActiveNotification

* Update Siren.swift

* Null safety and don't hardcode

The delay time what to consider is it called by notification center screen to bottom become constant
And appDidBecomeActiveWorkItem is used null safety

Co-authored-by: seokmin <b915e504de0a2413661138f2b724e58b3076ffba@dio.co.kr>
ArtSabintsev/Siren,ArtSabintsev/Siren