Revert "Use Jack to check build"

This reverts commit 8bc90fd2d6ccf70b65d2d3aad22b0453b86a262d.

This CL also impacts standard targets. With Jack enabled, a global
'make' without that CL produce ~287 dex files, with this CL, it
produces ~697 dex files.

Bug: 19069325
Change-Id: I39853da0cba8226f31037733edc420507d76c8c0
diff --git a/core/java.mk b/core/java.mk
index 3d37498..9e159fb 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -256,17 +256,14 @@
 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 := $(full_classes_jack)
-endif # !LOCAL_USE_JACK
+java_alternative_checked_module :=
 endif
 
 # TODO: It looks like the only thing we need from base_rules is