Go: Disable libartd by default

Free up some space in userdebug to make consistent with user. Go
doesn't have enough resources, really, anyways.

Frees up about 9M.

Bug: 62087184
Test: lunch gobo-userdebug && m && ls $OUT/system/lib/libartd*
Change-Id: I109bbbc59b71de48ca63ba64142148a50fb0af55
diff --git a/target/product/go_defaults_common.mk b/target/product/go_defaults_common.mk
index fbb9567..221aa8a 100644
--- a/target/product/go_defaults_common.mk
+++ b/target/product/go_defaults_common.mk
@@ -55,3 +55,5 @@
 PRODUCT_PROPERTY_OVERRIDES += dalvik.vm.heapgrowthlimit=128m
 PRODUCT_PROPERTY_OVERRIDES += dalvik.vm.heapsize=256m
 
+# Do not generate libartd.
+PRODUCT_ART_TARGET_INCLUDE_DEBUG_BUILD := false