The zip-archive script was having trouble pulling in data from gen/.
Instead use a separate 'angledata' folder.

BUG=angleproject:1810

Change-Id: I09eaf4766a8360c40af9335bed74a5dc347e05ad
Reviewed-on: https://chromium-review.googlesource.com/435518
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>