Update git submodules

Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to 271281a0af7e3832810b86dd4b2b3f9c7d382b7b
  - Merge "Chaging name of rhel resource directory to rpm"
  - Chaging name of rhel resource directory to rpm

    Changing name of rhel resource directory in "resources/pkg" from rhel to rpm due to platfrom independent repository for all distributions supporting RPM packages.

    Issue-ID: OOM-2150

    Change-Id: Ie5425df8b8550c618440586b495907f86c4cc509
    Signed-off-by: Jan Benedikt <j.benedikt@partner.samsung.com>