Support the test ACA through the service API rather than compile ifdef

Introduce an ACAType to select between the default (production) and
test ACA and add it to messages where the type of ACA makes a
difference.

Also replace the unused alternate ACA credentials with test ones.

BUG=chromium:660261
TEST=unit_tests

Change-Id: Ie7e164ceaa3b8b99397de598b4f05f2b92b38df9
Reviewed-on: https://chromium-review.googlesource.com/678854
Commit-Ready: Yves Arrouye <[email protected]>
Tested-by: Yves Arrouye <[email protected]>
Reviewed-by: Andrey Pronin <[email protected]>
5 files changed