fix: navigation in iOS hybrid app (#1266)

## 📜 Description

Fixed a problem of non-working `onMove` handler on iOS if package is
used in hybrid app on iOS 26.

## 💡 Motivation and Context

The problem is that we pick up a wrong controller. In case when you
navigate from hybrid app to RN app `rootViewController` may point to old
view controller that belongs to native app (which will be dismissed). If
we attach a view to the controller that has been detached - we will not
attach it to active window, because `willMove(to window` will never be
called (because old controller will not be attached to the window
again).

To fix this error I added a check to attach tracking view to
`rootViewController` only if its window is active (i. e. `!= nil`).
Otherwise we need to attach it `topViewController`.

## 📢 Changelog

<!-- High level overview of important changes -->
<!-- For example: fixed status bar manipulation; added new types
declarations; -->
<!-- If your changes don't affect one of platform/language below - then
remove this platform/language -->

### iOS

- use `topViewController` if `rootViewController.view.window == nil`

## 🤔 How Has This Been Tested?

Tested in Expensify app.

## 📸 Screenshots (if appropriate):

|Before|After|
|-------|-----|
|<video
src="https://github.com/user-attachments/assets/8debcf3d-a105-4080-94b8-bf421fb2300a">|<video
src="https://github.com/user-attachments/assets/4fa88ea8-a996-4392-985a-694d5f390d19">|

## 📝 Checklist

- [x] CI successfully passed
- [x] I added new mocks and corresponding unit-tests if library API was
changed

Author: kirillzyusko

ios/observers/movement/KeyboardTrackingView.swift

@@ -66,7 +66,14 @@ public final class KeyboardTrackingView: UIView {
   }
 
   @objc public func attachToTopmostView(toWindow window: UIWindow? = nil) {
-    guard let topView = (window?.rootViewController ?? UIApplication.topViewController())?.view else { return }
+    var topViewController = window?.rootViewController
+    if let rootVC = topViewController, let topView = rootVC.view, topView.window != nil {
+      // ok, attach
+    } else {
+      topViewController = UIApplication.topViewController()
+    }
+
+    guard let topView = topViewController?.view else { return }
 
     if currentAttachedView === topView { return }