Apply version-script to binder_ndk library.

Hides unintentionally exported symbols from the library.

Bug: http://b/69603741
Test: make
Change-Id: I4b952bbbeb8dca29cf8a2401d24cd5aabb536776
diff --git a/libs/binder/ndk/Android.bp b/libs/binder/ndk/Android.bp
index 5461b4f..d16502f 100644
--- a/libs/binder/ndk/Android.bp
+++ b/libs/binder/ndk/Android.bp
@@ -38,6 +38,8 @@
         "libbinder",
         "libutils",
     ],
+
+    version_script: "libbinder_ndk.map.txt",
 }
 
 ndk_headers {