[Extensions] Update ExtensionServiceTestBase et al to manifest v2

Update ExtensionServiceTestBase and all derived tests to use
manifest v2 extensions. Update old .crx files, Preferences files,
and dynamically-created extensions. Remove the allowance for
manifest v1 extensions.

Bug: 816679

Change-Id: Ib07447a9cde9017f250d8100d3e55a9fd790d48c
Reviewed-on: https://chromium-review.googlesource.com/1024642
Reviewed-by: Dominic Battré <battre@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553749}
24 files changed