Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Apex: Fixes branch checking

    With the move to upstream artifacts post-fraser the checks to use
    upstream artifacts were relying on BRANCH == 'master'. This doesn't
    scale as we preserve fraser functionality but add more branches like
    gambia. Therefore inversing the logic to accomodate for new branches.

    Change-Id: Ice17f6afd33744f44d253d320a194c3f6d02d8bf
    Signed-off-by: Tim Rozet <trozet@redhat.com>