Fix and enable JarJar in Java builds.

java.mk contained a target to enable JarJar in Java builds, but it was
being bypassed.  This change enabled JarJar as part of the build
process, and fixes a slight bug with the way it was set up.

Change-Id: If24113f399a168939a1a1d0738c5df57caf8d05f
diff --git a/core/java.mk b/core/java.mk
index 11b615f..137a730 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -197,7 +197,7 @@
 $(full_classes_jarjar_jar): PRIVATE_JARJAR_RULES := $(LOCAL_JARJAR_RULES)
 $(full_classes_jarjar_jar): $(full_classes_emma_jar) | $(JARJAR)
 	@echo JarJar: $@
-	$(hide) $(JARJAR) process $(PRIVATE_JARJAR_RULES) $< $@
+	$(hide) java -jar $(JARJAR) process $(PRIVATE_JARJAR_RULES) $< $@
 else
 $(full_classes_jarjar_jar): $(full_classes_emma_jar) | $(ACP)
 	@echo Copying: $@
@@ -205,7 +205,7 @@
 endif
 
 # Keep a copy of the jar just before proguard processing.
-$(full_classes_full_names_jar): $(full_classes_emma_jar) | $(ACP)
+$(full_classes_full_names_jar): $(full_classes_jarjar_jar) | $(ACP)
 	@echo Copying: $@
 	$(hide) $(ACP) $< $@