Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to 2a50615f814c28dd78e30b5b40e4636d4f6b7dfd
  - Remove the cleanup-directories test role
    
    This role is no longer needed after
    removing it's usage from the nfs role.
    
    Issue-ID: OOM-1902
    Change-Id: I3f4d27e769c9edc3caef1b0d85a61f071e3a3b2f
    Signed-off-by: Michal Zegan <m.zegan@samsung.com>
    
diff --git a/docs/submodules/oom/offline-installer.git b/docs/submodules/oom/offline-installer.git
index 863c0ad..2a50615 160000
--- a/docs/submodules/oom/offline-installer.git
+++ b/docs/submodules/oom/offline-installer.git
@@ -1 +1 @@
-Subproject commit 863c0ad7fd25c06efce969fedac85887b1fb7e73
+Subproject commit 2a50615f814c28dd78e30b5b40e4636d4f6b7dfd