Move DataSaver enabled pref to DRP component

This CL is mostly just a change in namespace and layer for the pref
name, but is a needed step for the rest of the pending refactoring.

Bug: 934399
Change-Id: Ied89e46878a05b0a937166995ba5e9b9e7a287d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1535481
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Robert Ogden <robertogden@chromium.org>
Cr-Commit-Position: refs/heads/master@{#643526}
15 files changed