Switch to use slang/rs_version.mk for consistency.

Change-Id: Ibfda53448570be58941133cb53c1bbb90391aa30
diff --git a/cpp/Android.mk b/cpp/Android.mk
index d0f42aa..7208789 100644
--- a/cpp/Android.mk
+++ b/cpp/Android.mk
@@ -12,15 +12,8 @@
 LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
-ifeq "REL" "$(PLATFORM_VERSION_CODENAME)"
-  RS_VERSION := $(PLATFORM_SDK_VERSION)
-else
-  # Increment by 1 whenever this is not a final release build, since we want to
-  # be able to see the RS version number change during development.
-  # See build/core/version_defaults.mk for more information about this.
-  RS_VERSION := "(1 + $(PLATFORM_SDK_VERSION))"
-endif
-local_cflags_for_rs_cpp += -DRS_VERSION=$(RS_VERSION)
+include frameworks/compile/slang/rs_version.mk
+local_cflags_for_rs_cpp += $(RS_VERSION_DEFINE)
 local_cflags_for_rs_cpp += -Wno-unused-parameter
 
 LOCAL_SRC_FILES := $(rs_cpp_SRC_FILES)