Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 9aac45a0fe0313c0bfe9d913165a03fc9f495e0c
  - Add k8s_conformance_serial in gates

    Change-Id: If3471e9b881a7e79ac2781dd00ba9d89fa0aced7
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 45a8dd1..9aac45a 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 45a8dd15b1bf241c83460213c743eb666fdab680
+Subproject commit 9aac45a0fe0313c0bfe9d913165a03fc9f495e0c