Add PLATFORM_MIN_SUPPORTED_TARGET_SDK_VERSION

Exposed as ro.build.version.min_supported_target_sdk build_property

Test: make
Bug: 63926630
Change-Id: I8084fd4c54d9c2fb5e2683430e2b3aaf4c5f4a7a
diff --git a/core/Makefile b/core/Makefile
index 521d78d..2850e59 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -337,6 +337,7 @@
 			PLATFORM_PREVIEW_SDK_VERSION="$(PLATFORM_PREVIEW_SDK_VERSION)" \
 			PLATFORM_VERSION_CODENAME="$(PLATFORM_VERSION_CODENAME)" \
 			PLATFORM_VERSION_ALL_CODENAMES="$(PLATFORM_VERSION_ALL_CODENAMES)" \
+			PLATFORM_MIN_SUPPORTED_TARGET_SDK_VERSION="$(PLATFORM_MIN_SUPPORTED_TARGET_SDK_VERSION)" \
 			BUILD_VERSION_TAGS="$(BUILD_VERSION_TAGS)" \
 			BUILD_FINGERPRINT="$(BUILD_FINGERPRINT_FROM_FILE)" \
 			$(if $(OEM_THUMBPRINT_PROPERTIES),BUILD_THUMBPRINT="$(BUILD_THUMBPRINT)") \