fix: policy sql insert with check

Author: phamhieu

example/next-storage/README.md

@@ -33,5 +33,5 @@ alter publication supabase_realtime add table profiles;
 -- Set up Storage!
 insert into storage.buckets (id, name) values ('avatars', 'avatars');
 create policy "Avatar images are publicly accessible." on storage.objects for select using ( bucket_id = 'avatars' );
-create policy "Anyone can upload an avatar." on storage.objects for insert using ( bucket_id = 'avatars' );
+create policy "Anyone can upload an avatar." on storage.objects for insert with check ( bucket_id = 'avatars' );
 ```