Manifest for Android N IOT Preview 4 (NIH40E)

Change-Id: I720815c9e004405a5b8fcdc878d33ccf673325f9
diff --git a/default.xml b/default.xml
index 0b003d5..a2bd55d 100644
--- a/default.xml
+++ b/default.xml
@@ -4,7 +4,7 @@
   <remote  name="aosp"
            fetch=".."
            review="https://android-review.googlesource.com/" />
-  <default revision="n-iot-preview-4"
+  <default revision="refs/tags/android-n-iot-preview-4"
            remote="aosp"
            sync-j="4" />