Build layoutlib create tests as part of sdk build.

LayoutLib Create tests are now built whenever LayoutLib create is built.

Change-Id: Id215e8690e435019579dba1734090a0d585f37e1
diff --git a/tools/layoutlib/create/Android.mk b/tools/layoutlib/create/Android.mk
index 9bd48ab..e6f0bc3 100644
--- a/tools/layoutlib/create/Android.mk
+++ b/tools/layoutlib/create/Android.mk
@@ -26,3 +26,6 @@
 
 include $(BUILD_HOST_JAVA_LIBRARY)
 
+# Build all sub-directories
+include $(call all-makefiles-under,$(LOCAL_PATH))
+