Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to 56af1f9d2c3e2d0b6529d71014d619619cf25933
  - Merge "Adding docker images collector requirement"
  - Adding docker images collector requirement

    Adding pyyaml to requirements as it's required by
    docker-images-collector.sh

    Issue-ID: OOM-2393

    Signed-off-by: Tomáš Levora <t.levora@partner.samsung.com>
    Change-Id: I52036a8f905fa50eecaddee062d73a38ad2ed9ca

diff --git a/docs/submodules/oom/offline-installer.git b/docs/submodules/oom/offline-installer.git
index 4fbf064..56af1f9 160000 (submodule)
--- a/docs/submodules/oom/offline-installer.git
+++ b/docs/submodules/oom/offline-installer.git
@@ -1 +1 @@
-Subproject commit 4fbf064cd826f350174c6f80ee9f4614b5aaf113
+Subproject commit 56af1f9d2c3e2d0b6529d71014d619619cf25933