update_engine: fixes to use chromeos-dbus-bindings generation

Add dbus-service-config.json and fix update_engine.xml to have the
correct DBus path.  Move both into dbus_bindings folder.

BUG=None
TEST=Successful build and tested generated bindings
CQ-DEPEND=CL:256827,CL:*204736

Change-Id: I7020940c17cc3cf085cf2ef38275ed3a16f37ceb
Reviewed-on: https://chromium-review.googlesource.com/255935
Reviewed-by: Alex Deymo <deymo@chromium.org>
Tested-by: Timothy Jennison <tjennison@google.com>
Commit-Queue: Timothy Jennison <tjennison@google.com>
diff --git a/main.cc b/main.cc
index 763e823..0fbfdaa 100644
--- a/main.cc
+++ b/main.cc
@@ -30,7 +30,7 @@
 #include "update_engine/terminator.h"
 #include "update_engine/update_attempter.h"
 extern "C" {
-#include "update_engine/update_engine.dbusserver.h"
+#include "update_engine/org.chromium.UpdateEngineInterface.dbusserver.h"
 }
 #include "update_engine/utils.h"