GitLab

* Adding ability to configure values requested by the Feed team, except
  2 that are not available in Configuration class.
* Updating FeedProcessScopeFactory to consume configuration.
* Adding javatests to cover the code.

Bug: 886972
Change-Id: Ib38fe2ea062fa7014ff5e4ecff02150f24e96f67
Reviewed-on: https://chromium-review.googlesource.com/1248121Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Filip Gorski <fgorski@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595881}