Update git submodules

* Update docs/submodules/availability from branch 'master'
  - Add Requirement Analyze for HA API in HA Analyze Document

    JIRA: HA-38

    Add HA Scenario Analyze for HA API Design in the HA Analyze Document,
    in order to make links between the HA Analyze Document and other documents
    in HA project

    Change-Id: I7856452745e7c169cfd0e7dfbfba19c120804af9
    Signed-off-by: Kecheng_Guo <1552778@tongji.edu.cn>

diff --git a/docs/submodules/availability b/docs/submodules/availability
index 15a4164..ba452c8 160000 (submodule)
--- a/docs/submodules/availability
+++ b/docs/submodules/availability
@@ -1 +1 @@
-Subproject commit 15a4164a7995aca710d0016ee9e2e1f7a508044b
+Subproject commit ba452c88a1f117b022f7d1207212a80a9447687a