fix for vm entry point in android

Author: git-elliot

lib/src/services_impls/host_scanner_service_flutter_impl.dart

@@ -11,13 +11,15 @@ import 'package:universal_io/io.dart';
 import 'package:network_tools/src/services/impls/host_scanner_service_impl.dart';
 
 /// Scans for all hosts in a subnet.
+@pragma('vm:entry-point')
 class HostScannerServiceFlutterImpl extends HostScannerServiceImpl {
   /// Scans for all hosts in a particular subnet (e.g., 192.168.1.0/24)
   /// Set maxHost to higher value if you are not getting results.
   /// It won't firstHostId again unless previous scan is completed due to heavy
   /// resource consumption.
   /// [resultsInAddressAscendingOrder] = false will return results faster but not in order
   @override
+  @pragma('vm:entry-point')
   Stream<ActiveHost> getAllPingableDevices(
     String subnet, {
     int firstHostId = HostScannerService.defaultFirstHostId,