Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Set volume_device_name=vdb for apex"
  - Set volume_device_name=vdb for apex

    Change-Id: I40a8359ea8ef868f79a02dcb824e80cd8b3385d1
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index ca6539a..9c9d5f6 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit ca6539a8f8c7f608623cdd578d2d606322f06370
+Subproject commit 9c9d5f688b7043eb2422b85ec239b2c9aee9ebff