Update git submodules

* Update docs/submodules/sdnc/oam.git from branch 'master'
  to 018fccd75b035292c12b2ba6ebe98800dc5db8bb
  - Merge "Add a new Ansible playbook for PNF software upgrade"
  - Add a new Ansible playbook for PNF software upgrade

    Use sub-operations from 3GPP (downloadNESw, installNESw and activateNESw) to
    implement PNF software upgrade.

    Change-Id: I5aa42ca480b022c644c806bb4dc49cb01d331e2c
    Issue-ID: SDNC-677
    Signed-off-by: Enbo Wang <wangenbo@huawei.com>

diff --git a/docs/submodules/sdnc/oam.git b/docs/submodules/sdnc/oam.git
index 0fb3e0e..018fccd 160000 (submodule)
--- a/docs/submodules/sdnc/oam.git
+++ b/docs/submodules/sdnc/oam.git
@@ -1 +1 @@
-Subproject commit 0fb3e0e11b347f001353df62b428f5e2d5ef1f9c
+Subproject commit 018fccd75b035292c12b2ba6ebe98800dc5db8bb