Revert "Move most version variable out to relase configs."

Revert submission 25118098-ap11

Reason for revert: DroidMonitor-triggered revert due to breakage https://android-build.corp.google.com/builds/quarterdeck?branch=git_aosp-main-future&target=errorprone-trunk_staging&lkgb=10993884&lkbb=10995208&fkbb=10994141, bug b/307480895

Reverted changes: /q/submissionid:25118098-ap11

Change-Id: I2bc1fc4a9e92a3c4cf8acba3dbaaf61e6fb0774e
diff --git a/core/tasks/cts.mk b/core/tasks/cts.mk
index b9f0988..d05640c 100644
--- a/core/tasks/cts.mk
+++ b/core/tasks/cts.mk
@@ -37,7 +37,7 @@
   cts_platform_release_path := cts/tests/tests/os/assets/platform_releases.txt
   cts_platform_release_string := $(shell cat $(cts_platform_release_path))
 
-  ifneq (REL,$(PLATFORM_VERSION_CODENAME))
+  ifeq ($(RELEASE_PLATFORM_VERSION_CODENAME_REL),)
     ifeq (,$(findstring $(PLATFORM_VERSION),$(cts_platform_version_string)))
       define error_msg
         ============================================================