Copy platforms and samples from ndk/ source tree.

The idea is to allow developing the NDK in the open, while
having the platforms and samples under a private branch until
the corresponding release are open-sourced.

Change-Id: Iee995fb6c4d3ee1387dea7486e599e079c9e4c6d

ndk/samples/native-activity/src/Barf.java

@@ -0,0 +1,7 @@
+/* This is only needed because the NDK build system currently
+ * can't deal with an .apk that doesn't have Java code.
+ */
+
+public class Barf {
+    
+}