Migrate libandroid headers to ndk_headers.

Test: make native
Bug: http://b/30465923
Change-Id: I0ef0b3630670241c4efd22515b6ab13eb41a81b3
diff --git a/include/android/native_window.h b/include/android/native_window.h
index cf07f1a..b60b9f1 100644
--- a/include/android/native_window.h
+++ b/include/android/native_window.h
@@ -26,6 +26,8 @@
 #ifndef ANDROID_NATIVE_WINDOW_H
 #define ANDROID_NATIVE_WINDOW_H
 
+#include <sys/cdefs.h>
+
 #include <android/rect.h>
 
 #ifdef __cplusplus