This was added briefly because the timer was
pausing when the app was in the background (sometimes).
I read somewhere using a BroadcastReceiver prevents the timer
from being slept by Android, which turned out to be false (on a Pixel
4).
The actual solution was disabling battery optimizations, so this
broadcast receiver is now redundant.
This was supposed to solve the timer stopping sometimes
when the application was in the background.
It was actually stopping because of battery optimizations.