Manifest for Android 8.1.0 Release 51 (OPM8.181105.002)

Change-Id: I1cab2f6cd5c59f03397a37ecf4dc6ca7b43c8399
diff --git a/default.xml b/default.xml
index 422681f..0b068ab 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_r48"
+  <default revision="refs/tags/android-8.1.0_r51"
            remote="aosp"
            sync-j="4" />