Update git submodules

* Update docs/submodules/policy/engine.git from branch 'master'
  to b831c6a3df8e1dc9017ae5e8ad002dc3b1002aab
  - Merge "Format java POLICY-SDK-APP"
  - Format java POLICY-SDK-APP

    As a result of doing command maven reformat, these files are
    now changed.

    Updated licenses.

    Issue-ID: POLICY-2133
    Change-Id: I19a8dd70eb10c0d879b97635f7780ab7f92a1753
    Signed-off-by: Pamela Dragosh <pdragosh@research.att.com>

diff --git a/docs/submodules/policy/engine.git b/docs/submodules/policy/engine.git
index 710011b..b831c6a 160000 (submodule)
--- a/docs/submodules/policy/engine.git
+++ b/docs/submodules/policy/engine.git
@@ -1 +1 @@
-Subproject commit 710011b4fb147bf100c52c4b0425160bba88a0fd
+Subproject commit b831c6a3df8e1dc9017ae5e8ad002dc3b1002aab