Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Apex: Use CSIT to gate snapshot promotion

    Now that we have CSIT suite passing, we want to use that to gate our
    snapshot promotion rather than tempest.

    Change-Id: Ifddaf7921da15150a253021ee5ca64ab2fd438ff
    Signed-off-by: Tim Rozet <trozet@redhat.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 545447c..37a3845 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 545447c4ce40100e30ae20cb3dd25b982a20f308
+Subproject commit 37a38451ebf17ae617037844ed0f6b7eeab5985e