Update git submodules

* Update plugins/gitiles from branch 'master'
  to 8c220bff6dd6a9b14f7c96487b3a904433d4599a
  - Redirect anonymous users without read access to login
    
    Trigger login redirection for anonymous users who attempt to
    access a project they cannot read, including requests for
    non-existent projects to avoid leaking project existence.
    
    Change-Id: I5b53ad4ee03882c122c8bf59ba8f6dd9c674d440
    
  - Separate login redirect utility from MenuFilter
    
    Used for the followup change which uses the same login redirect
    utility.
    
    Change-Id: Ib5e6d3ba8827b7fb419b943650ba26372c4fece9
    
diff --git a/plugins/gitiles b/plugins/gitiles
index 5ee7f57..8c220bf 160000
--- a/plugins/gitiles
+++ b/plugins/gitiles
@@ -1 +1 @@
-Subproject commit 5ee7f57486a1c1b5121e9979b8496706ae2891e5
+Subproject commit 8c220bff6dd6a9b14f7c96487b3a904433d4599a