Add missing JIT stuff in make files

Was causing core.oat to not be created.

Bug: 19524713
Change-Id: I5da005fd36f9682623fdda9931280997b59c2681
diff --git a/build/Android.common_test.mk b/build/Android.common_test.mk
index da50d53..547e92e 100644
--- a/build/Android.common_test.mk
+++ b/build/Android.common_test.mk
@@ -46,6 +46,9 @@
 # Do you want interpreter tests run?
 ART_TEST_INTERPRETER ?= $(ART_TEST_FULL)
 
+# Do you want JIT tests run?
+ART_TEST_JIT ?= $(ART_TEST_FULL)
+
 # Do you want optimizing compiler tests run?
 ART_TEST_OPTIMIZING ?= $(ART_TEST_FULL)