rename initWithFlutterView to initWithController (#9208)

packages/flutter_tools/templates/create/ios.tmpl/Runner/AppDelegate.m.tmpl

@@ -15,7 +15,7 @@
 {{#withPluginHook}}
   FlutterViewController *flutterController =
       (FlutterViewController *)self.window.rootViewController;
-  _{{pluginProjectName}} = [[{{pluginClass}} alloc] initWithFlutterView:flutterController];
+  _{{pluginProjectName}} = [[{{pluginClass}} alloc] initWithController:flutterController];
 {{/withPluginHook}}
     return YES;
 }

packages/flutter_tools/templates/plugin/ios.tmpl/Classes/pluginClass.h.tmpl

 #import <Flutter/Flutter.h>
 
 @interface {{pluginClass}} : NSObject
-- initWithFlutterView:(FlutterViewController *)flutterView;
+- initWithController:(FlutterViewController *)controller;
 @end

packages/flutter_tools/templates/plugin/ios.tmpl/Classes/pluginClass.m.tmpl

@@ -3,12 +3,12 @@
 @implementation {{pluginClass}} {
 }
 
-- (instancetype)initWithFlutterView:(FlutterViewController *)flutterView {
+- (instancetype)initWithController:(FlutterViewController *)controller {
   self = [super init];
   if (self) {
     FlutterMethodChannel *channel = [FlutterMethodChannel
         methodChannelWithName:@"{{projectName}}"
-           binaryMessenger:flutterView];
+           binaryMessenger:controller];
     [channel setMethodCallHandler:^(FlutterMethodCall *call,
                                     FlutterResultReceiver result) {
       if ([@"getPlatformVersion" isEqualToString:call.method]) {