Package ddmlib-prebuilt with CTS.

This ensures that CTS is using a compatible ddmlib.
diff --git a/core/tasks/cts.mk b/core/tasks/cts.mk
index 0a796f0..f697347 100644
--- a/core/tasks/cts.mk
+++ b/core/tasks/cts.mk
@@ -25,6 +25,7 @@
 endif
 CTS_HOST_JAR := $(HOST_OUT_JAVA_LIBRARIES)/cts.jar
 
+DDMLIB_JAR := $(HOST_OUT_JAVA_LIBRARIES)/ddmlib-prebuilt.jar
 junit_host_jar := $(HOST_OUT_JAVA_LIBRARIES)/junit.jar
 HOSTTESTLIB_JAR := $(HOST_OUT_JAVA_LIBRARIES)/hosttestlib.jar
 
@@ -55,6 +56,8 @@
 # Copy executable to CTS directory
 	$(hide) $(ACP) -fp $(CTS_HOST_JAR) $(PRIVATE_DIR)/tools
 	$(hide) $(ACP) -fp $(CTS_EXECUTABLE_PATH) $(PRIVATE_DIR)/tools
+# Copy ddmlib prebuilt jar
+	$(hide) $(ACP) -fp $(DDMLIB_JAR) $(PRIVATE_DIR)/tools
 # Copy junit jar
 	$(hide) $(ACP) -fp $(PRIVATE_JUNIT_HOST_JAR) $(PRIVATE_DIR)/tools
 # Copy hosttestlib jar