update_engine: Use GetDlcsToUpdate() instead of GetInstalled()

The meaning of GetInstalled() DBus in dlcservice have changed. So we need
to get the list of DLCs that ought to be updated from the new DBus
GetDlcsToUpdate().

Also rename all dlc_module_ids to dlc_ids.

BUG=chromium:1071654
TEST=cros_workon_make --board reef --test update_engine

Cq-Depend: chromium:2157669
Change-Id: I02e450a1fd75f8b387eb8a107c9c8a32f3e01e6e
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2163441
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Andrew Lassalle <andrewlassalle@chromium.org>
Reviewed-by: Jae Hoon Kim <kimjae@chromium.org>
Commit-Queue: Amin Hassani <ahassani@chromium.org>
diff --git a/client_library/client_dbus.h b/client_library/client_dbus.h
index a032d21..74fcce3 100644
--- a/client_library/client_dbus.h
+++ b/client_library/client_dbus.h
@@ -44,7 +44,7 @@
                      bool at_user_request) override;
 
   bool AttemptInstall(const std::string& omaha_url,
-                      const std::vector<std::string>& dlc_module_ids) override;
+                      const std::vector<std::string>& dlc_ids) override;
 
   bool SetDlcActiveValue(bool is_active, const std::string& dlc_id) override;
 
diff --git a/client_library/include/update_engine/client.h b/client_library/include/update_engine/client.h
index 9bda0b9..f734733 100644
--- a/client_library/include/update_engine/client.h
+++ b/client_library/include/update_engine/client.h
@@ -54,11 +54,10 @@
   //     empty indicates update_engine should use its default value. Note that
   //     update_engine will ignore this parameter in production mode to avoid
   //     pulling untrusted updates.
-  // |dlc_module_ids|
+  // |dlc_ids|
   //     A list of DLC module IDs.
-  virtual bool AttemptInstall(
-      const std::string& omaha_url,
-      const std::vector<std::string>& dlc_module_ids) = 0;
+  virtual bool AttemptInstall(const std::string& omaha_url,
+                              const std::vector<std::string>& dlc_ids) = 0;
 
   // Same as above but return the entire struct instead.
   virtual bool GetStatus(UpdateEngineStatus* out_status) const = 0;