* Create `PushHandlingWakeLock` to start a foreground service:
When receiving a push and scheduling the notification fetching, several problems can happen:
1. Some async operation is waiting for a timeout and it takes way longer than that to finish (i.e. timeout of 10s but it took 30s to advance).
2. The same, but when starting new coroutines. I've seen the time between scheduling a coroutine and it running sometimes take up to 1 minute.
3. Notification fetching can be scheduled immediately, but it can take a while to actually run because the OS understands the app is now in Doze.
Having a wakelock that runs as soon as the push handling starts fixes these: it continues the previous wakelock held by either Firebase or the UnifiedPush distributor.
* Acquire the wakelock as soon as we received the pushes in both receivers
* Also release the wakelock ahead of time if possible
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