Fix image name conflict (r8,r7,r8)

The same image names were used in two DC contexts where different
sets of dialogs should have been displayed (instead of repeating)
This renames one set.

Signed-off-by: Ron Stone <ronald.stone@windriver.com>
Change-Id: I05dc6e8de50c2dedaeded706d6a695ef705dc5a3

doc/source/dist_cloud/kubernetes/create-an-upgrade-orchestration-using-horizon-9f8c6c2f3706.rst

@@ -72,9 +72,9 @@ You must have completed the procedure in
           Offline subcloud is not skipped. Applicable only when the strategy is
           created to a single subcloud.
 
-       .. figure:: figures/create-strategy.png
+       .. figure:: figures/create-upgrade-strategy.png
 
-       .. figure:: figures/create-strategy-2.png
+       .. figure:: figures/create-upgrade-strategy-2.png
 
            Create an orchestration strategy