Make RELEASE_PLATFORM_VERSION a release config flag to set platform version.

Bug: 282838389
Test: Treehugger
Merged-In: Ic6dacbdee7d2408aa8b25b4df59bf9bbc566d747
Change-Id: Ie61a7d986c2b8fe2c16117f6678b9e5a71711647
diff --git a/core/version_util.mk b/core/version_util.mk
index d4ce113..d3fcdc2 100644
--- a/core/version_util.mk
+++ b/core/version_util.mk
@@ -14,17 +14,17 @@
 # limitations under the License.
 #
 
-#
-
 ALLOWED_VERSIONS := $(call allowed-platform-versions,\
   $(MIN_PLATFORM_VERSION),\
   $(MAX_PLATFORM_VERSION),\
-  $(DEFAULT_PLATFORM_VERSION))
+  $(RELEASE_PLATFORM_VERSION))
 
-ifndef TARGET_PLATFORM_VERSION
-  TARGET_PLATFORM_VERSION := $(DEFAULT_PLATFORM_VERSION)
+ifdef TARGET_PLATFORM_VERSION
+  $(error Do not set TARGET_PLATFORM_VERSION directly. Use RELEASE_PLATFORM_VERSION. value: $(TARGET_PLATFORM_VERSION))
 endif
 
+TARGET_PLATFORM_VERSION := $(RELEASE_PLATFORM_VERSION)
+
 ifeq (,$(filter $(ALLOWED_VERSIONS), $(TARGET_PLATFORM_VERSION)))
   $(warning Invalid TARGET_PLATFORM_VERSION '$(TARGET_PLATFORM_VERSION)', must be one of)
   $(error $(ALLOWED_VERSIONS))