Update git submodules

* Update docs/submodules/apex from branch 'stable/euphrates'
  - Fix licenses to be Apache 2.0

    Change-Id: I53f3596685b83e995498b5fdb804561fed6dc38b
    Signed-off-by: Tim Rozet <trozet@redhat.com>
    (cherry picked from commit 16fa09bb892289f3997ef14ed6cbe5a278ee342a)

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 4eb4cc3..4e73312 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 4eb4cc36098057aae95c755ffeb3b2843ddd0435
+Subproject commit 4e7331201ef12419de64061c326604e4a9049be2