Update git submodules

* Update docs/submodules/usecase-ui.git from branch 'master'
  to 7bda6e4948e9e38dc2c3f0e01af9e0390b8548db
  - docs: adjust the size of user guide picture
    
    Change-Id: If30e434bd187c0f29708937a6ac6bfee005f941d
    Issue-ID: USECASEUI-306
    Signed-off-by: cyuamber <xuranyjy@chinamobile.com>
    
1 file changed