Add vts to build in ninja

Bug: 27687012
Change-Id: Icb94e3eee71a8f54f13f868fa2461b2063e7ca6d
diff --git a/core/ninja.mk b/core/ninja.mk
index 5bb09ae..9d0ff9a 100644
--- a/core/ninja.mk
+++ b/core/ninja.mk
@@ -63,6 +63,7 @@
 	userdataimage \
 	userdebug \
 	valgrind-test-art% \
+	vts \
 	win_sdk \
 	winsdk-tools