Address review feedback: extract GIF type identifier to variable

Author: ritoban23

packages/image_picker/image_picker_ios/ios/image_picker_ios/Sources/image_picker_ios/FLTImagePickerImageUtil.m

@@ -118,11 +118,13 @@ + (GIFInfo *)scaledGIFImage:(NSData *)data
                   maxHeight:(NSNumber *)maxHeight {
   NSMutableDictionary<NSString *, id> *options = [NSMutableDictionary dictionary];
   options[(NSString *)kCGImageSourceShouldCache] = @YES;
+  NSString *gifTypeIdentifier;
   if (@available(iOS 14.0, *)) {
-    options[(NSString *)kCGImageSourceTypeIdentifierHint] = UTTypeGIF.identifier;
+    gifTypeIdentifier = UTTypeGIF.identifier;
   } else {
-    options[(NSString *)kCGImageSourceTypeIdentifierHint] = (NSString *)kUTTypeGIF;
+    gifTypeIdentifier = (NSString *)kUTTypeGIF;
   }
+  options[(NSString *)kCGImageSourceTypeIdentifierHint] = gifTypeIdentifier;
 
   CGImageSourceRef imageSource =
       CGImageSourceCreateWithData((__bridge CFDataRef)data, (__bridge CFDictionaryRef)options);