Initial import of new NDK into donut tree

ndk/sources/samples/two-libs/second.c

@@ -0,0 +1,11 @@
+#include "first.h"
+#include <jni.h>
+
+jint
+Java_com_example_TwoLib_TwoLib_add( JNIEnv*  env,
+                                    jobject  this,
+                                    jint     x,
+                                    jint     y )
+{
+    return first(x, y);
+}