Use Jack to check build

Of modules that are to be compiled with Jack.

Change-Id: Ie8bd00f67f09c0e5ed8fe650f5131a3dfc29e277
diff --git a/core/java.mk b/core/java.mk
index 9e159fb..3d37498 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -256,14 +256,17 @@
 LOCAL_RESOURCE_DIR := $(LOCAL_INTERMEDIATE_SOURCE_DIR)/renderscript/res $(LOCAL_RESOURCE_DIR)
 endif
 
+java_alternative_checked_module :=
+ifdef full_classes_jar
+ifneq ($(strip $(LOCAL_USE_JACK)),true)
 # All of the rules after full_classes_compiled_jar are very unlikely
 # to fail except for bugs in their respective tools.  If you would
 # like to run these rules, add the "all" modifier goal to the make
 # command line.
-ifdef full_classes_jar
 java_alternative_checked_module := $(full_classes_compiled_jar)
 else
-java_alternative_checked_module :=
+java_alternative_checked_module := $(full_classes_jack)
+endif # !LOCAL_USE_JACK
 endif
 
 # TODO: It looks like the only thing we need from base_rules is