Allow control of jack used for compilation

Version of Jack used to compile a module can now be control from
a dedicated mk located in prebuilts/sdk/tools

Bug: 24564814

(cherry picked from commit b68c9a498d1e2c631eb6e8c9092d4d5775402083)

Change-Id: I7809dc966026ff94b5cb2daa7e2c63762ca4768d
diff --git a/core/main.mk b/core/main.mk
index 8610492..e20128b 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -312,6 +312,12 @@
 # The pdk (Platform Development Kit) build
 include build/core/pdk_config.mk
 
+#
+# -----------------------------------------------------------------
+# Jack version configuration
+include $(TOPDIR)prebuilts/sdk/tools/jack_versions.mk
+include $(TOPDIR)prebuilts/sdk/tools/jack_for_module.mk
+
 # -----------------------------------------------------------------
 ###
 ### In this section we set up the things that are different