[Background Fetch] Remove uploads feature flag.

Bug: 774054
Change-Id: Id043c7bfde953ce86addc358856418eb3104c2bb
Reviewed-on: https://chromium-review.googlesource.com/c/1416134
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624082}
8 files changed