[iOS] Need a test for bug #145539: Uploading an animated GIF from the

[iOS] Need a test for bug #145539: Uploading an animated GIF from the
photo library uploads a JPEG
https://bugs.webkit.org/show_bug.cgi?id=148849

Reviewed by Daniel Bates.

* ManualTests/ios/image-file-uploads-as-original-type.html: Added.
On the Mac, file upload tests use EventSender::beginDragWithFiles. This
functionality doesn't exist on iOS, so we'll add a manual test.
This tests that the first few bytes of the selected file are "GIF".

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@189410 268f45cc-cd09-0410-ab3c-d52691b4dbfc