fix(iam): prevent crash when dismissing IAM during view hierarchy changes (#1641)

Fix crash in -[OSInAppMessageViewController dismissCurrentInAppMessage:withVelocity:]

The crash occurred when setInAppMessagingPaused:YES was called while the IAM's
view hierarchy was in an inconsistent state (e.g., during orientation change).
The code attempted to modify Auto Layout constraints on a messageView that was
no longer a subview of self.view, causing an NSLayoutConstraint exception.

Added a guard check to return out early if messageView.superview != self.view.

Author: nan-li

iOS_SDK/OneSignalSDK/OneSignalInAppMessages/UI/OSInAppMessageViewController.m

@@ -516,9 +516,14 @@ - (void)dismissCurrentInAppMessage:(BOOL)up withVelocity:(double)velocity {
     if (self.dismissalTimer)
         [self.dismissalTimer invalidate];
 
-    // If the rendering event never occurs any constraints being adjusted for dismissal will be nil
-    // and we should bypass dismissal adjustments and animations and skip straight to the OSMessagingController callback for dismissing
-    if (!self.didPageRenderingComplete) {
+    // Return early and skip constraint adjustments/animations if:
+    // - Page rendering never completed (constraints would be nil)
+    // - messageView is not valid or not a direct subview of self.view (prevents crashes when
+    //   dismissal is triggered while the view hierarchy is in an inconsistent state)
+    if (!self.didPageRenderingComplete ||
+        !self.messageView ||
+        self.messageView.superview != self.view)
+    {
         [self dismissViewControllerAnimated:false completion:nil];
         [self.delegate messageViewControllerWasDismissed:self.message displayed:NO];
         return;