Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 72f5c70d944780dd98e070e82363a58a20c38b66
  - Merge "Remove unused private field and replace repeated string with constants."
  - Remove unused private field and replace repeated string with constants.

    Remove unused private field and replace repeated string with constants.

    Change-Id: I2e68cfb5e7d83e626cb2e274b7ea2989352f2867
    Issue-ID: SO-1490
    Signed-off-by: h00397475 <hena.choudhury@huawei.com>

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index bb56dd6..72f5c70 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit bb56dd69512406f8d8bb709b8c84e7d09b4a239c
+Subproject commit 72f5c70d944780dd98e070e82363a58a20c38b66