Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 1640ac602723737c8f15a9a84046e709f7230a1c
  - Merge "New GroupLevel DeleteE2EServiceInstance flow"
  - New GroupLevel DeleteE2EServiceInstance flow

    Modified the subprocess 'DoDeleteE2EServiceInstance'
    to support Group level instances.

    Change-Id: I8dfd154bc6eb9c9f7c7dc932bdce215a3b9fd800
    Issue-ID: SO-1393
    Signed-off-by: sarada prasad sahoo <sarada.prasad.sahoo@huawei.com>

diff --git a/docs/submodules/so.git b/docs/submodules/so.git
index 11b69a4..1640ac6 160000 (submodule)
--- a/docs/submodules/so.git
+++ b/docs/submodules/so.git
@@ -1 +1 @@
-Subproject commit 11b69a4a70a70b8eb5b9216ae3f4360e651f12b3
+Subproject commit 1640ac602723737c8f15a9a84046e709f7230a1c