Updated git submodules

Project: policy/engine master aec7ea166403a3319cf558460881164834694c1f

Upgrade springframework 4.3.18.RELEASE

To resolve security issue for 4.3.15.RELEASE and also
have a single place where the dependency is defined for
the sub-modules.

NOTE: 4.2.0.RELEASE is left alone in Policy SDK App
due to Portal SDK dependency.

Issue-ID: POLICY-1063
Change-Id: Ibdc464b16b4771faccb2c8c472efa7fbcbf3352c
Signed-off-by: Pamela Dragosh <pdragosh@research.att.com>

diff --git a/docs/submodules/policy/engine.git b/docs/submodules/policy/engine.git
index 55e795c..aec7ea1 160000 (submodule)
--- a/docs/submodules/policy/engine.git
+++ b/docs/submodules/policy/engine.git
@@ -1 +1 @@
-Subproject commit 55e795c171cabb7800effcbbb75bed0224b92691
+Subproject commit aec7ea166403a3319cf558460881164834694c1f