Plugin template uses new channel name (#9453)

packages/flutter_tools/templates/plugin/lib/projectName.dart.tmpl

diff --git a/packages/flutter_tools/templates/plugin/lib/projectName.dart.tmpl b/packages/flutter_tools/templates/plugin/lib/projectName.dart.tmpl
index 0350ecd..b61b95f 100644
--- a/packages/flutter_tools/templates/plugin/lib/projectName.dart.tmpl
+++ b/packages/flutter_tools/templates/plugin/lib/projectName.dart.tmpl
@@ -3,8 +3,8 @@
 import 'package:flutter/services.dart';
 
 class {{pluginDartClass}} {
-  static const PlatformMethodChannel _channel =
-      const PlatformMethodChannel('{{projectName}}');
+  static const MethodChannel _channel =
+      const MethodChannel('{{projectName}}');
 
   static Future<String> get platformVersion =>
       _channel.invokeMethod('getPlatformVersion');