Don't use Jack embedded library

This is a temporary workround to avoid intermittent failure on
build server for ub-conscrypt

Bug: 20132430
Change-Id: I67e57436595d77fee86b3724df1fdff70850e9e9
diff --git a/Android.mk b/Android.mk
index c5683fb..616d617 100644
--- a/Android.mk
+++ b/Android.mk
@@ -25,7 +25,7 @@
 	$$(call copy-file-to-target)
 
 $$(_cpsttrp_sdk_intermediates)/classes.jack: PRIVATE_JACK_VM_ARGS := $(DEFAULT_JACK_VM_ARGS)
-$$(_cpsttrp_sdk_intermediates)/classes.jack: PRIVATE_JACK_EXTRA_ARGS := $(DEFAULT_JACK_EXTRA_ARGS)
+$$(_cpsttrp_sdk_intermediates)/classes.jack: PRIVATE_JACK_EXTRA_ARGS := $(DEFAULT_JACK_EXTRA_ARGS) -D jack.classpath.default-libraries=false
 $$(_cpsttrp_sdk_intermediates)/classes.jack : $$(_cpsttrp_src_jar) $(JILL_JAR) $(JACK_JAR)
 	$$(call transform-jar-to-jack)