Support all active codenames for BOARD_SYSTEMSDK_VERSIONS

Use PLATFORM_VERSION_ALL_CODENAMES to construct PLATFORM_SYSTEMSDK_VERSIONS
so that both S and T are accepted while T is active but S is not finalized.

Bug: 186121492
Test: treehugger
Change-Id: Ia9f58c5986c717cb2882e2fc4daadb2b3874c6b5
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 181ea62..f32ea76 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -229,7 +229,7 @@
 ifeq (REL,$(PLATFORM_VERSION_CODENAME))
   PLATFORM_SYSTEMSDK_VERSIONS += $(PLATFORM_SDK_VERSION)
 else
-  PLATFORM_SYSTEMSDK_VERSIONS += $(PLATFORM_VERSION_CODENAME)
+  PLATFORM_SYSTEMSDK_VERSIONS += $(subst $(comma),$(space),$(PLATFORM_VERSION_ALL_CODENAMES))
 endif
 PLATFORM_SYSTEMSDK_VERSIONS := $(strip $(sort $(PLATFORM_SYSTEMSDK_VERSIONS)))
 .KATI_READONLY := PLATFORM_SYSTEMSDK_VERSIONS