Indicates whether the device allows the application to access the location service.
Check this property before you start location updates to
determine if the device has location services enabled and that the application has access to them.
On iOS, if this property is false and you start location updates
anyway, the device prompts the user with a confirmation
panel asking whether to enable location services for the application.
On Android, the property returns false if the application has no permission to access location. If you start the location service updates, the user receives location permission request (unless already granted or permanently denied). Before starting the location service updates, you can query to check whether the application has location permission.