Revert platform version to 12

Bug: 204295952
Test: N/A
Change-Id: I899af9326e95b4fcfb778f84b748f56834d54ca8
Merged-In: I7f87d189030e97f47dc81b756d1397b4aa65daf0
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 488b0a4..25cefc2 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -88,7 +88,7 @@
 # The last stable version name of the platform that was released.  During
 # development, this stays at that previous version, while the codename indicates
 # further work based on the previous version.
-PLATFORM_VERSION_LAST_STABLE := 12L
+PLATFORM_VERSION_LAST_STABLE := 12
 .KATI_READONLY := PLATFORM_VERSION_LAST_STABLE
 
 # These are the current development codenames, if the build is not a final