generate_gradle.py: Enable --all by default

Seems to be fast enough now!

Bug: 620034
Change-Id: I8d47bb8dbd63bb60678bd55cb23696b7b2304f95
Reviewed-on: https://chromium-review.googlesource.com/772432
Commit-Queue: agrieve <agrieve@chromium.org>
Reviewed-by: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516879}
2 files changed