Fix crash when clicking "Undo" twice
Store `workState` in local variable

So we don’t need to fetch it again
Change `REQUEST_ALARM_RING` to be more than 0

Since 0 can sometimes be used similar to `null` or `false`
Clarify restoring saved timers

And fix not restoring state after alarm ringing
Fix Android Studio warning

“Not annotated paramater overrides @NotNull paramater”