update_engine: Make policy UpdateCheckParams processing easier

Currently there are a ton of arguments from UpdateCheckParams that is
passed around in the udpate_attampter.cc. With this CL UpdateCheckParams
is directy passed and this simplies the logic.

BUG=b:171829801
TEST=cros_workon_make --board reef --test update_enigne

Change-Id: If454f6393fc6e28d41fa5d14d184f0db32e8bd19
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2504453
Commit-Queue: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Jae Hoon Kim <kimjae@chromium.org>
diff --git a/mock_update_attempter.h b/mock_update_attempter.h
index d502222..96d93fd 100644
--- a/mock_update_attempter.h
+++ b/mock_update_attempter.h
@@ -32,17 +32,7 @@
 
   MOCK_METHOD(void,
               Update,
-              (const std::string& app_version,
-               const std::string& omaha_url,
-               const std::string& target_channel,
-               const std::string& lts_tag,
-               const std::string& target_version_prefix,
-               bool rollback_allowed,
-               bool rollback_data_save_requested,
-               int rollback_allowed_milestones,
-               bool rollback_on_channel_downgrade,
-               bool obey_proxies,
-               bool interactive),
+              (const chromeos_update_manager::UpdateCheckParams& params),
               (override));
 
   MOCK_METHOD1(GetStatus, bool(update_engine::UpdateEngineStatus* out_status));