[Extensions] Remove obsolete storage manifest test

ChromeManifestTest.StorageAPIManifestVersionAvailability tests that
the chrome.storage API is not available to manifest v1 extensions. This
behavior is now enforced (and much more thorouhgly tested) through the
features unittests.

Remove the test.

Bug: 816679

Change-Id: I8e313127cd43885fab8b49a9a3acfb58dbf2d4c9
Reviewed-on: https://chromium-review.googlesource.com/1007624
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550023}
2 files changed