Fix build on older APIs, take 2

Use PLATFORM_SDK_VERSION, not PLATFORM_VERSION
as the latter has periods.

Bug: 131089111

Change-Id: Ic3108cd2a9a71dd3db9b9633a8347ff950ca93e5
diff --git a/gralloc/Android.mk b/gralloc/Android.mk
index 8576e91..e0b0b85 100644
--- a/gralloc/Android.mk
+++ b/gralloc/Android.mk
@@ -32,7 +32,7 @@
 
 LOCAL_MODULE := gralloc.goldfish.default
 LOCAL_CFLAGS:= -DLOG_TAG=\"gralloc\" -Wno-missing-field-initializers
-LOCAL_CFLAGS:= -DPLATFORM_VERSION=$(PLATFORM_VERSION)
+LOCAL_CFLAGS:= -DPLATFORM_SDK_VERSION=$(PLATFORM_SDK_VERSION)
 ifeq ($(TARGET_USE_PAN_DISPLAY),true)
 LOCAL_CFLAGS += -DUSE_PAN_DISPLAY=1
 endif
diff --git a/gralloc/gralloc.cpp b/gralloc/gralloc.cpp
index 97e6857..3f2c025 100644
--- a/gralloc/gralloc.cpp
+++ b/gralloc/gralloc.cpp
@@ -89,7 +89,7 @@
         .unregisterBuffer = gralloc_unregister_buffer,
         .lock = gralloc_lock,
         .unlock = gralloc_unlock,
-#if PLATFORM_VERSION > 9
+#if PLATFORM_SDK_VERSION >= 28
         .validateBufferSize = NULL,
         .getTransportSize = NULL,
 #endif