Update git submodules

* Update docs/submodules/appc.git from branch 'master'
  to e612868cb3405886d104a9940c95da0fdfac218c
  - Used constants in the place of dup literals

    Sonar fix

    Issue-ID: APPC-1557
    Change-Id: I4b52b9febabd0fae8aa098004aeba0ef9a085710
    Signed-off-by: Jegadeesh Babu <jegabab1@in.ibm.com>
  - Used constants to replace duplicated literals

    Sonar Fix

    Issue-ID: APPC-1555
    Change-Id: I3943003c7fa37aed95e138f03a3fe4b8f48b75ce
    Signed-off-by: Jegadeesh Babu <jegabab1@in.ibm.com>

diff --git a/docs/submodules/appc.git b/docs/submodules/appc.git
index 82a5634..e612868 160000 (submodule)
--- a/docs/submodules/appc.git
+++ b/docs/submodules/appc.git
@@ -1 +1 @@
-Subproject commit 82a563486818bf28e8a40fbda1fed7069d9e0d70
+Subproject commit e612868cb3405886d104a9940c95da0fdfac218c