Update git submodules

Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to c07a4d7fc0f25e9cfea300cbce8fc624ad922384
  - Merge "Add prepare-kubectl role"
  - Add prepare-kubectl role

    This role is used to prepare for kubectl role tests.
    It may also be used when any other test needs installed
    kubectl, for example when verifying kubernetes cluster
    setup.
    Both cases are a bit different.

    Change-Id: Ie7a065c571d94f40cfd64c3eba78af3e84b3f08a
    Issue-ID: OOM-1908
    Signed-off-by: Michal Zegan <m.zegan@samsung.com>