Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 57b9a52289ab4c4590a9cb7c5a537c3484bfe28a
  - Merge "Sonar comments fixed Removed commented lines/ Change static string litrals name according to the guidelines. Issue-ID: SO-1490"
  - Sonar comments fixed
    Removed commented lines/ Change static string litrals name according to the guidelines.
    Issue-ID: SO-1490

    Change-Id: I4ffee97269f0f0bdcb23f5b297df8fddb0c133f1
    Signed-off-by: Subhosree Pan <subhosree.pan1@huawei.com>

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 947249a..57b9a52 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 947249a450e6c849710b750867a9b92300ff384f
+Subproject commit 57b9a52289ab4c4590a9cb7c5a537c3484bfe28a