Apply version-script to libjnigraphics library

Hide unintentionally exported symbols, validate that symbols mentioned
in the map file actually exported by the library.

Bug: http://b/69603741
Test: make
Change-Id: I80ec35b715b28dea45ebfbd216130c2c946c6668
diff --git a/native/graphics/jni/Android.bp b/native/graphics/jni/Android.bp
index 9426148..942eafd 100644
--- a/native/graphics/jni/Android.bp
+++ b/native/graphics/jni/Android.bp
@@ -37,6 +37,7 @@
             ldflags: ["-Wl,--hash-style=both"],
         },
     },
+    version_script: "libjnigraphics.map.txt",
 }
 
 // The headers module is in frameworks/native/Android.bp.