Update git submodules

* Update docs/submodules/usecase-ui.git from branch 'master'
  to a6854b6aab4b4fee1f859f0694c2fe55694b16f4
  - Merge "Automation adds index.rst"
  - Automation adds index.rst
    
    Issue-ID: CIMAN-376
    
    Change-Id: I49885f6a6a16461c6d82c3b1705628e941730912
    Signed-off-by: lf-jobbuilder <releng+lf-jobbuilder@linuxfoundation.org>
    
1 file changed