[iOS] Stop swizzling the |init| method of CameraController.

ios/chrome/browser/ui/qr_scanner/camera_controller.h

Index: ios/chrome/browser/ui/qr_scanner/camera_controller.h
diff --git a/ios/chrome/browser/ui/qr_scanner/camera_controller.h b/ios/chrome/browser/ui/qr_scanner/camera_controller.h
index 9a346c2198bdf4094a384a2c54a245e43c61ba0a..fdbf560d9ee8bcc582a0b08ac5c5771f73eba882 100644
--- a/ios/chrome/browser/ui/qr_scanner/camera_controller.h
+++ b/ios/chrome/browser/ui/qr_scanner/camera_controller.h
@@ -67,9 +67,9 @@ enum CameraState {
 
 - (instancetype)init NS_UNAVAILABLE;
 
-// Initializes the controller with the |delegate|.
-- (instancetype)initWithDelegate:(id<CameraControllerDelegate>)delegate
-    NS_DESIGNATED_INITIALIZER;
+// Returns a new controller with the |delegate|.
++ (instancetype)cameraControllerWithDelegate:
+    (id<CameraControllerDelegate>)delegate;
 
 // Returns the app's authorization in regards to the camera.
 - (AVAuthorizationStatus)getAuthorizationStatus;