ActiveStorage: Pass useCapture to UJS listener

Closes [@hotwired/turborails#243][].

Set the `useCapture` parameter of [addEventListener][] to `true` so that
cancelling the event occurs early enough in the process so that the
resulting upload is cancelled.

[@hotwired/turborails#243]: hotwired/turbo#243 (comment)
[addEventListener]: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener#parameters

Co-authored-by: Javan Makhmali <javan@basecamp.com>

activestorage/app/javascript/activestorage/ujs.js

@@ -9,7 +9,7 @@ export function start() {
   if (!started) {
     started = true
     document.addEventListener("click", didClick, true)
-    document.addEventListener("submit", didSubmitForm)
+    document.addEventListener("submit", didSubmitForm, true)
     document.addEventListener("ajax:before", didSubmitRemoteElement)
   }
 }