Prepare release 0.2.3 (4003)

Change-Id: I785c3c51ba59c7528e664eff06de4b432604ecdf
diff --git a/RELEASE_NOTES.rst b/RELEASE_NOTES.rst
index 043d810..c173dc7 100644
--- a/RELEASE_NOTES.rst
+++ b/RELEASE_NOTES.rst
@@ -1,3 +1,16 @@
+NFD-Android version 0.2.3
+-------------------------
+
+- WiFi Direct connectivity helper
+- NDN ping client
+- Permanent face and route management mechanisms
+
+NFD-Android version 0.2.2
+-------------------------
+
+- NFD updated to version 0.5.0
+- Add route deletion GUI
+
 NFD-Android version 0.2.1
 -------------------------