update_engine: Move DLC metadata ownership to update_engine

Add dbus messages so dlcservice can let update_engine know when a DLC is
installed or uninstalled.

BUG=chromium:912666
TEST=unittests, install and uninstall DLCs on DUT.

Cq-Depend: chromium:2112994,chromium:2113254
Change-Id: I35374504afcdaf96b099e343cabe072fc18f1022
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2113134
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Jae Hoon Kim <kimjae@chromium.org>
Tested-by: Andrew Lassalle <andrewlassalle@chromium.org>
Commit-Queue: Andrew Lassalle <andrewlassalle@chromium.org>
diff --git a/dbus_service.cc b/dbus_service.cc
index b1cc298..cd71488 100644
--- a/dbus_service.cc
+++ b/dbus_service.cc
@@ -110,6 +110,12 @@
   return common_->ResetStatus(error);
 }
 
+bool DBusUpdateEngineService::SetDlcActiveValue(brillo::ErrorPtr* error,
+                                                bool is_active,
+                                                const string& dlc_id) {
+  return common_->SetDlcActiveValue(error, is_active, dlc_id);
+}
+
 bool DBusUpdateEngineService::GetStatusAdvanced(ErrorPtr* error,
                                                 StatusResult* out_status) {
   UpdateEngineStatus status;