Refactor notification channels registration

[tindn]

Currently, this method https://github.com/Path-Check/background-geolocation-android/blob/master/src/main/java/com/marianhello/bgloc/sync/NotificationHelper.java#L88 allows registration of all channels, and it's being used by https://github.com/Path-Check/background-geolocation-android/blob/master/src/main/java/com/marianhello/bgloc/BackgroundGeolocationFacade.java#L85.

However, the sync service channel is already being registered here https://github.com/Path-Check/background-geolocation-android/blob/master/src/main/java/com/marianhello/bgloc/sync/SyncAdapter.java#L76 and the service channel is being registered here https://github.com/Path-Check/background-geolocation-android/blob/master/src/main/java/com/marianhello/bgloc/service/LocationServiceImpl.java#L225.

Therefore, the registerAllChannels is only effectively registering the permission channel. If this is the case, this method should be refactored to be just permissions channel.