[Extensions] Update more test extensions to manifest v2

Update chrome/test/data/extensions/permissions_increase/* to
manifest v2. This required changing background_page to
background.

Bug: 816679
Change-Id: I99afd26749acf1c7d8bf9b737200370de5324ba5
Reviewed-on: https://chromium-review.googlesource.com/946549
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540704}
3 files changed