brillo_update_payload should require simg2img.
am: db537c18ef

Change-Id: Iabd4e66f7f5f64a2c85c9ed08b018eca41b7c747
diff --git a/Android.mk b/Android.mk
index 528aa76..ff12e59 100644
--- a/Android.mk
+++ b/Android.mk
@@ -1007,6 +1007,7 @@
 LOCAL_MODULE_TAGS := optional
 LOCAL_REQUIRED_MODULES := \
     delta_generator \
-    shflags
+    shflags \
+    simg2img
 include $(BUILD_PREBUILT)
 endif  # HOST_OS == linux