feat(auth,macos): add support for publish and addApplicationDelegate on macOS FlutterPluginRegistrar (#17518)

* feat(auth,macos): add support for `publish` and `addApplicationDelegat`e on macOS FlutterPluginRegistrar

* chore: refactor code

* chore: use TARGET_OS_IPHONE

* chore: fix formatting

Author: SelaseKay

packages/firebase_analytics/firebase_analytics/ios/firebase_analytics/Sources/firebase_analytics/FirebaseAnalyticsMessages.g.swift

@@ -134,7 +134,7 @@ func deepHashFirebaseAnalyticsMessages(value: Any?, hasher: inout Hasher) {
 /// Generated class from Pigeon that represents data sent in messages.
 struct AnalyticsEvent: Hashable {
   var name: String
-  var parameters: [String?: Any?]? = nil
+  var parameters: [String?: Any?]?
 
   // swift-format-ignore: AlwaysUseLowerCamelCase
   static func fromList(_ pigeonVar_list: [Any?]) -> AnalyticsEvent? {

packages/firebase_app_installations/firebase_app_installations/ios/firebase_app_installations/Sources/firebase_app_installations/IdChangedStreamHandler.swift

@@ -45,8 +45,8 @@ class IdChangedStreamHandler: NSObject, FlutterStreamHandler {
     }
   }
 
-  public func onListen(withArguments _: Any?,
-                       eventSink events: @escaping FlutterEventSink) -> FlutterError? {
+  func onListen(withArguments _: Any?,
+                eventSink events: @escaping FlutterEventSink) -> FlutterError? {
     eventSink = events
 
     installationIDObserver = NotificationCenter.default.addObserver(
@@ -63,7 +63,7 @@ class IdChangedStreamHandler: NSObject, FlutterStreamHandler {
     return nil
   }
 
-  public func onCancel(withArguments _: Any?) -> FlutterError? {
+  func onCancel(withArguments _: Any?) -> FlutterError? {
     if let observer = installationIDObserver {
       NotificationCenter.default.removeObserver(observer)
       installationIDObserver = nil

packages/firebase_auth/firebase_auth/example/macos/Runner/AppDelegate.swift

@@ -6,4 +6,8 @@ class AppDelegate: FlutterAppDelegate {
   override func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
     return true
   }
+
+  override func applicationSupportsSecureRestorableState(_ app: NSApplication) -> Bool {
+    return true
+  }
 }

packages/firebase_auth/firebase_auth/ios/firebase_auth/Sources/firebase_auth/FLTFirebaseAuthPlugin.m

@@ -152,18 +152,12 @@ + (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
 
   [registrar addMethodCallDelegate:instance channel:channel];
 
-#if TARGET_OS_OSX
-  // TODO(Salakar): Publish does not exist on MacOS version of
-  // FlutterPluginRegistrar.
-  // TODO(Salakar): addApplicationDelegate does not exist on MacOS version of
-  // FlutterPluginRegistrar. (https://github.com/flutter/flutter/issues/41471)
-  SetUpFirebaseAuthHostApi(registrar.messenger, instance);
-  SetUpFirebaseAuthUserHostApi(registrar.messenger, instance);
-#else
   [registrar publish:instance];
   [registrar addApplicationDelegate:instance];
   SetUpFirebaseAuthHostApi(registrar.messenger, instance);
   SetUpFirebaseAuthUserHostApi(registrar.messenger, instance);
+
+#if TARGET_OS_IPHONE
   SetUpMultiFactorUserHostApi(registrar.messenger, instance);
   SetUpMultiFactoResolverHostApi(registrar.messenger, instance);
   SetUpMultiFactorTotpHostApi(registrar.messenger, instance);