Update git submodules

* Update docs/submodules/appc.git from branch 'master'
  to d7f35b76ef535dc620d873423d6a77d2e575782b
  - Add method to escape json strings

    All backslash escape characters are being stripped out of strings.
    They need to be added back to strings containing json data.

    Change-Id: Ic8d9ba95da904b96f65598752133971f8c324694
    Signed-off-by: Patrick Brady <patrick.brady@att.com>
    Issue-ID: APPC-1576

diff --git a/docs/submodules/appc.git b/docs/submodules/appc.git
index 8de52a3..d7f35b7 160000 (submodule)
--- a/docs/submodules/appc.git
+++ b/docs/submodules/appc.git
@@ -1 +1 @@
-Subproject commit 8de52a3d6112f919ee019f401a51d30b7cbde164
+Subproject commit d7f35b76ef535dc620d873423d6a77d2e575782b