Check if user has enabled BACKGROUND_LOCATION when the app launches

[nateridderman]

Starting with Android 11, apps cannot request location in the background unless the user has explicitly enabled this in the OS settings for the app. A permissions dialog in-app is not good enough. This includes WorkManager jobs if the user is not in the app at the time. Therefore we should check if the user has enabled this and if not, alert them somehow when they launch the app.

https://developer.android.com/about/versions/oreo/background-location-limits#tuning-behavior
https://developer.android.com/training/location/background