Update git submodules

* Update docs/submodules/apex from branch 'stable/danube'
  - Adding kickstart file for iso verify

    Change-Id: If2712b15d23ce1453e7d3ee1aa4df92b8e537856
    Signed-off-by: Dan Radez <dradez@redhat.com>
    (cherry picked from commit 854199f3485680c1193b3cb07caf477298371714)

diff --git a/docs/submodules/apex b/docs/submodules/apex
index b7c0066..1a10b8e 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit b7c0066de509b3eb2e1264966eff12cff49472e1
+Subproject commit 1a10b8e7559ca75f5ac624d561303cf20bac9bc9