Add openfst to external, as used by GoogleTTS

Moved from GoogleTTS

Change-Id: I6bc6bdadaa53bd0f810b88443339f6d899502cc8
diff --git a/README.android b/README.android
new file mode 100644
index 0000000..6d822ec
--- /dev/null
+++ b/README.android
@@ -0,0 +1,4 @@
+Openfst openfst-1.2.10
+Updated to Google CL27738347
+
+Modified to use stlport, Android.mk file added.
\ No newline at end of file