authpolicy: Add even more authpolicy integration tests

Adds tests for
- policy fetch with actual policy data,
- policy override behavior and
- error behavior for policy fetch.

BUG=chromium:664441
TEST=Compiles, tests work fine

Change-Id: I00f9d21694faa3ab5b185254893265cc91ca5af2
Reviewed-on: https://chromium-review.googlesource.com/445899
Commit-Ready: Lutz Justen <ljusten@chromium.org>
Tested-by: Lutz Justen <ljusten@chromium.org>
Tested-by: Roman Sorokin <rsorokin@chromium.org>
Reviewed-by: Lutz Justen <ljusten@chromium.org>
Reviewed-by: Roman Sorokin <rsorokin@chromium.org>
14 files changed