Add blueprint_tools as default target

Bug: 38351765
Test: rm out -rf && m -j && stat out/soong/host/*/bin/bpfmt

Change-Id: I60ededa1b13fb575616162d6dc1b0b8159f97f20
diff --git a/core/main.mk b/core/main.mk
index 62a9c5f..bc4ed04 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -409,6 +409,8 @@
 include $(BUILD_SYSTEM)/pdk_fusion_modules.mk
 endif # PDK_FUSION_PLATFORM_ZIP
 
+droid_targets : blueprint_tools
+
 endif # dont_bother
 
 endif # ONE_SHOT_MAKEFILE