Update git submodules

* Update docs/submodules/usecase-ui.git from branch 'master'
  to c7a9cb23b403083f6a8b9d5b9a8a6de25e5c1502
  - Service instance lifecycle management
    
    Change-Id: I5513d8f59b02ae400e5b406e46a27967af23621d
    Issue-ID: USECASEUI-218
    Signed-off-by: guochuyicmri <guochuyi@chinamobile.com>
    
1 file changed