Update git submodules

* Update docs/submodules/apex from branch 'stable/danube'
  - Merge "Adds apex owned scenario release notes" into stable/danube
  - Adds apex owned scenario release notes

    Change-Id: Ia7b50b99b82a01d347ba673e354d80cbb65e608f
    Signed-off-by: Tim Rozet <trozet@redhat.com>
    (cherry picked from commit e6f86a1b3f8dcdd0adf3edf3b0d3bf824e39313b)

diff --git a/docs/submodules/apex b/docs/submodules/apex
index 6e95a5a..b4af8e1 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit 6e95a5aa856d61f85543ed8e0f654ef90afb953e
+Subproject commit b4af8e13fd656423fe7275d6f37b7cfee10cd1aa