[Extensions] Update more test extensions to manifest v2

Update chrome/test/data/extensions/api_test/system to manifest v2.
This involved complying to manifest v2's CSP requirements.

Bug: 816679
Change-Id: I14b3f139770722a7312786c582ca0e74fef892db
Reviewed-on: https://chromium-review.googlesource.com/946906
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#540728}
3 files changed