Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Move gerrit comment logic to its own file

    this file will become too complicated to escape inside the job
    definition.

    Change-Id: I3e167bee5d315a7ff3b52e7274b68c3146dfbd03
    Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index af98447..69591a5 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit af98447e8f2faaa3cfc8a0aa9299092999976625
+Subproject commit 69591a53f460f0a174b274f643a44f9102d2d78a