Register for VOIP keep alive handler

voip_keep_alive_handler

BOOL ret = [[UIApplication sharedApplication] setKeepAliveTimeout:600 handler:^(void) {
    if (updating_location) {
        [location_manager stopUpdatingLocation];
        NSLog(@"Keep alive: Stopping location updates");
    }
    else {
        [location_manager startUpdatingLocation];
        NSLog(@"Keep alive: Starting location updates");
    }
        
    updating_location = !updating_location;
}];
    
if (ret) {
    NSLog(@"Keep alive handler registered");
}