Update git submodules

* Update docs/submodules/availability from branch 'master'
  - Modify format error in overview doc

    Modify format error in overview doc

    JIRA: HA-28

    Change-Id: I580b5ede0457ed5d6f38f03cea8acea6dffa0646
    Signed-off-by:fuqiao@chinamobile.com

diff --git a/docs/submodules/availability b/docs/submodules/availability
index 54961e9..bc37f3b 160000 (submodule)
--- a/docs/submodules/availability
+++ b/docs/submodules/availability
@@ -1 +1 @@
-Subproject commit 54961e9deb343b3d45d0ae0295729af207ec8451
+Subproject commit bc37f3b74db17b2ca550695c634f0b85e0d700a5