Update git submodules

* Update docs/submodules/apex from branch 'master'
  - Merge "Change qemu-img resize unit"
  - Change qemu-img resize unit

    Docs read:
    size
        is the disk image size in bytes. Optional suffixes "k" or "K"
        (kilobyte, 1024) "M" (megabyte, 1024k) and "G" (gigabyte, 1024M)
         and T (terabyte, 1024G) are supported.  "b" is ignored.

    MB is technically invalid and for somereason only aarch has complained
    thus far

    Change-Id: Ic152a0edab17ac1cdb5afc0791bb0353b95f94b8
    Signed-off-by: Dan Radez <dradez@redhat.com>

diff --git a/docs/submodules/apex b/docs/submodules/apex
index ceb8b28..45b4a3d 160000 (submodule)
--- a/docs/submodules/apex
+++ b/docs/submodules/apex
@@ -1 +1 @@
-Subproject commit ceb8b2863c0483fd850d49c7545a8b8fc6a34bbd
+Subproject commit 45b4a3da4e3fbfb438d64088cb99d3e43902bca4