Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to e51fa00446f6a8bc4d01a433d2ebaa11a08a1b9f
  - Merge "Define constant in place of literals Constants are declared and used in place of literals Issue-ID: SO-1490"
  - Define constant in place of literals
    Constants are declared and used in place of literals
    Issue-ID: SO-1490

    Change-Id: I8891e3aad24b29b4c951d995df0192437304d06e
    Signed-off-by: h00397475 <hena.choudhury@huawei.com>

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 40593fe..e51fa00 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 40593fe19cb687c0be239bac84c8662715e37c01
+Subproject commit e51fa00446f6a8bc4d01a433d2ebaa11a08a1b9f