Clean-up and make the art script usable on target.

Also add a phony target to build what's needed to use it.

Change-Id: I0bca6b0cbe921653de05fec0ae0cbbff63df580e
diff --git a/tools/Android.mk b/tools/Android.mk
index d3be17f..9a96f7a 100644
--- a/tools/Android.mk
+++ b/tools/Android.mk
@@ -27,3 +27,13 @@
 	@echo "Copy: $(PRIVATE_MODULE) ($@)"
 	$(copy-file-to-new-target)
 	$(hide) chmod 755 $@
+
+# Copy the art shell script to the target's bin directory
+include $(CLEAR_VARS)
+LOCAL_MODULE_CLASS := EXECUTABLES
+LOCAL_MODULE := art
+include $(BUILD_SYSTEM)/base_rules.mk
+$(LOCAL_BUILT_MODULE): $(LOCAL_PATH)/art $(ACP)
+	@echo "Copy: $(PRIVATE_MODULE) ($@)"
+	$(copy-file-to-new-target)
+	$(hide) chmod 755 $@