Make Code More Efficient

As pointed out by Zoontek, there is a function to find the top view controller in React Native. Importing that function, and then updated the topViewController to use that function.

Author: kurt-anderson-prod

ios/PhotoLibrary/RNPermissionHandlerPhotoLibrary.m

@@ -1,4 +1,5 @@
 #import "RNPermissionHandlerPhotoLibrary.h"
+#import <React/RCTUtils.h>
 
 @import Photos;
 @import PhotosUI;
@@ -57,15 +58,7 @@ - (void)openLimitedPhotoLibraryPickerWithResolver:(RCTPromiseResolveBlock _Nonnu
       return reject(@"cannot_open_limited_picker", @"Photo library permission isn't limited", nil);
     }
 
-    UIViewController* topViewController = [[UIApplication sharedApplication].keyWindow rootViewController];
-    UIViewController* presentedViewController = topViewController.presentedViewController;
-
-    while (presentedViewController = topViewController.presentedViewController) {
-      topViewController = presentedViewController;
-      presentedViewController = topViewController.presentedViewController;
-    }
-
-    UIViewController* rootViewController = [[UIApplication sharedApplication].keyWindow rootViewController];
+    UIViewController *topViewController = RCTPresentedViewController();
     [[PHPhotoLibrary sharedPhotoLibrary] presentLimitedLibraryPickerFromViewController:topViewController];
 
     resolve(@(true));