Manifest for Android N MR2 Preview 2

Change-Id: I9356c18c031832dcab84f7a151cb712dda0ff6c2
diff --git a/default.xml b/default.xml
index 7835d53..6353deb 100644
--- a/default.xml
+++ b/default.xml
@@ -3,7 +3,7 @@
 
   <remote  name="aosp"
            fetch=".." />
-  <default revision="refs/tags/android-n-mr2-preview-1"
+  <default revision="refs/tags/android-n-mr2-preview-2"
            remote="aosp"
            sync-j="4" />