Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to 52eb50721e990e277ed8729225faff305dee11da
  - Merge "Dockerfile and build script for Ubuntu"
  - Dockerfile and build script for Ubuntu

    Dockerfile that allows building a Systemd
    compliant Ubuntu image (for Ubuntu releases
    that support it).

    A build script for building the image.

    Change-Id: I3456e40e7ac96e611e957b2912405f9030dc0f04
    Issue-ID: OOM-1774
    Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>

diff --git a/docs/submodules/oom/offline-installer.git b/docs/submodules/oom/offline-installer.git
index a058898..52eb507 160000 (submodule)
--- a/docs/submodules/oom/offline-installer.git
+++ b/docs/submodules/oom/offline-installer.git
@@ -1 +1 @@
-Subproject commit a058898611c812462cbd8334d062c3746cd464fc
+Subproject commit 52eb50721e990e277ed8729225faff305dee11da