Increase rootfs size to 4gb for amd64-generic-tot-asan-informational.

TEST=Manual inspection
BUG=chromium:697967

Change-Id: I421600e944f1929fba5393896424aa62bbecf8d1
Reviewed-on: https://chromium-review.googlesource.com/457108
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Trybot-Ready: Steven Bennetts <stevenjb@chromium.org>
Tested-by: Steven Bennetts <stevenjb@chromium.org>
2 files changed