Fix the paths for local engine builds targeting the host platform (#3855)

packages/flutter_tools/lib/src/runner/flutter_command_runner.dart

@@ -87,14 +87,14 @@ class FlutterCommandRunner extends CommandRunner {
             'Path to your host Debug out directory (i.e. the one that runs on your workstation, not a device),\n'
             'if you are building Flutter locally.\n'
             'This path is relative to --engine-src-path. Not normally required.',
-        defaultsTo: 'out/Debug/');
+        defaultsTo: 'out/host_debug_unopt/');
     argParser.addOption('host-release-build-path',
         hide: !verboseHelp,
         help:
             'Path to your host Release out directory (i.e. the one that runs on your workstation, not a device),\n'
             'if you are building Flutter locally.\n'
             'This path is relative to --engine-src-path. Not normally required.',
-        defaultsTo: 'out/Release/');
+        defaultsTo: 'out/host_debug/');
 
     argParser.addOption('android-debug-build-path',
         hide: !verboseHelp,