Manifest for Android 8.1.0 Release 39 (OPM4.171019.021.Q1)

Change-Id: Id86c3193c27187c93d6f74a18f6136f5ffea9b69
diff --git a/default.xml b/default.xml
index 1a96670..091f96c 100644
--- a/default.xml
+++ b/default.xml
@@ -4,7 +4,7 @@
   <remote  name="aosp"
            fetch=".."
            review="https://android-review.googlesource.com/" />
-  <default revision="refs/tags/android-8.1.0_r33"
+  <default revision="refs/tags/android-8.1.0_r39"
            remote="aosp"
            sync-j="4" />