Change origin's fetch address to '..'

This is a common trick to support cloning repos using different
transport methods, notably https (public) vs sso (internal).
diff --git a/default.xml b/default.xml
index 17752c1..01f61b5 100644
--- a/default.xml
+++ b/default.xml
@@ -1,9 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <manifest>
-  <remote
-    name="origin"
-    fetch="https://android-kvm.googlesource.com/" />
+  <remote name="origin" fetch=".." />
   <default remote="origin" revision="master" />
+
   <project path="kvmtool" name="kvmtool" />
   <project path="kvm-unit-tests" name="kvm-unit-tests" />
   <project path="linux" name="linux" />