Update git submodules

* Update docs/submodules/policy/distribution.git from branch 'master'
  to 99def6ddf75d44a8c8c02144cb49b346a82bdaf6
  - Add multi-thread support in FileSystemReceptionHander

    By adding multi-thread support in FileSystemReceptionHander, we can have
    a more thorough s3p test to test performance & stablity in multithread
    situations.

    Change-Id: Id263435531e26dcbadfbda6f82b26ac54a72ba1a
    Issue-ID: POLICY-1274
    Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>

diff --git a/docs/submodules/policy/distribution.git b/docs/submodules/policy/distribution.git
index 42370a0..99def6d 160000 (submodule)
--- a/docs/submodules/policy/distribution.git
+++ b/docs/submodules/policy/distribution.git
@@ -1 +1 @@
-Subproject commit 42370a06ea7681b6e422b1d5739ec4d6c1287103
+Subproject commit 99def6ddf75d44a8c8c02144cb49b346a82bdaf6