Adding missing dependencies for vbmetaimage-nodeps

Bug: 143513520
Test: `make vbmetaimage-nodeps` then checks the value of
      PRIVATE_AVB_VBMETA_SIGNING_ARGS appears in ./out/verbose.log.gz

Change-Id: I2eac2b2d319a46f3c3ecb56df8c6b56925a4d596
diff --git a/core/Makefile b/core/Makefile
index 9946d42..b1bddbf 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -3625,6 +3625,8 @@
 	$(build-vbmetaimage-target)
 
 .PHONY: vbmetaimage-nodeps
+vbmetaimage-nodeps: PRIVATE_AVB_VBMETA_SIGNING_ARGS := \
+    --algorithm $(BOARD_AVB_ALGORITHM) --key $(BOARD_AVB_KEY_PATH)
 vbmetaimage-nodeps:
 	$(build-vbmetaimage-target)
 endif # BUILDING_VBMETA_IMAGE