FIxes Swift name for the new protocol. (#289)

Author: XiangtianDai

Example/Auth/SwiftSample/ViewController.swift

@@ -19,7 +19,7 @@ import UIKit
 import FirebaseCommunity.FirebaseAuth
 import GoogleSignIn
 
-final class ViewController: UIViewController, UITextFieldDelegate, FIRAuthUIDelegate {
+final class ViewController: UIViewController, UITextFieldDelegate, AuthUIDelegate {
   /// The profile image for the currently signed-in user.
   @IBOutlet weak var profileImage: UIImageView!
 

Firebase/Auth/Source/Public/FIRAuthUIDelegate.h

@@ -24,7 +24,8 @@ NS_ASSUME_NONNULL_BEGIN
 /** @protocol FIRAuthUIDelegate
     @brief A protocol to handle user interface interactions for Firebase Auth.
  */
-@protocol FIRAuthUIDelegate  <NSObject>
+FIR_SWIFT_NAME(AuthUIDelegate)
+@protocol FIRAuthUIDelegate <NSObject>
 
 /** @fn presentViewController:animated:completion:
     @brief If implemented, this method will be invoked when Firebase Auth needs to display a view