vndk/window.h must be C compatible

Test: added a c compatibility test
Bug: 36725813
Change-Id: Ic7e1c8b50e1818707a9a457d84ed74e7e6c816c8
diff --git a/libs/nativewindow/include/vndk/window.h b/libs/nativewindow/include/vndk/window.h
index 89585f3..310e1e5 100644
--- a/libs/nativewindow/include/vndk/window.h
+++ b/libs/nativewindow/include/vndk/window.h
@@ -236,6 +236,8 @@
     ANATIVEWINDOW_QUERY_YDPI = 0x10003,
 };
 
+typedef enum ANativeWindowQuery ANativeWindowQuery;
+
 /*
  * hook used to retrieve information about the native window.
  *