Conditionally set dbus group in init rc.

Change-Id: I9958b56502ee5eecdb3ca279779c6a66774b88f5
diff --git a/Android.mk b/Android.mk
index 6c70e12..84331cb 100644
--- a/Android.mk
+++ b/Android.mk
@@ -352,7 +352,12 @@
 
 endif  # defined(BRILLO)
 
+ifeq ($(BRILLO_USE_DBUS),1)
+LOCAL_INIT_RC := update_engine-dbus.rc
+else  # BRILLO_USE_DBUS != 1
 LOCAL_INIT_RC := update_engine.rc
+endif  # BRILLO_USE_DBUS == 1
+
 include $(BUILD_EXECUTABLE)
 
 ifeq ($(BRILLO_USE_DBUS),1)
diff --git a/update_engine-dbus.rc b/update_engine-dbus.rc
new file mode 100644
index 0000000..69fc7af
--- /dev/null
+++ b/update_engine-dbus.rc
@@ -0,0 +1,4 @@
+service update_engine /system/bin/update_engine --logtostderr --foreground
+    class late_start
+    user root
+    group root system dbus inet
diff --git a/update_engine.rc b/update_engine.rc
index 69fc7af..e62d83c 100644
--- a/update_engine.rc
+++ b/update_engine.rc
@@ -1,4 +1,4 @@
 service update_engine /system/bin/update_engine --logtostderr --foreground
     class late_start
     user root
-    group root system dbus inet
+    group root system inet