Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to 8620b2be770895ffca1385f3a8a57b9422ecf126
  - Merge "Add configurable etcd storage feature"
  - Add configurable etcd storage feature

    Plus the option to have etcd on tmpfs (volatile storage) for little
    bigger (maybe) speed (NOT FOR PRODUCTION DEPLOYMENT!).

    Issue-ID: OOM-2058

    Change-Id: I0bbfc4fbae7f6b46e2fae49656437cd6748efd49
    Signed-off-by: Petr Ospalý <p.ospaly@partner.samsung.com>

diff --git a/docs/submodules/oom/offline-installer.git b/docs/submodules/oom/offline-installer.git
index 30bb2a6..8620b2b 160000 (submodule)
--- a/docs/submodules/oom/offline-installer.git
+++ b/docs/submodules/oom/offline-installer.git
@@ -1 +1 @@
-Subproject commit 30bb2a6332d4e18f0a31e955e9285bf0a3d12411
+Subproject commit 8620b2be770895ffca1385f3a8a57b9422ecf126