Update git submodules

* Update src/sonic-utilities from branch 'broadcom_sonic'
  to 279d8ca317103aee4df82f2afecd6083a598ce09
  - [JIRA SONIC-694] Placeholder for VRF Lite support
    Merge from PRS: sonic-net/sonic-utilities#525
    Adding CLI support for VRF configuration and show commands
    Fixing vlan member add and port-channel member add clis for new
    interface vrf schema
    Making all ipv4 & ipv6 clis vrf aware.
    Modifying code which access interface config db.
    
    Dev Sanity:
    http://10.59.132.240:9009/projects/csg_sonic/sanity/logs/dev-sanity-td3-td3-01/sonic_sanity_190616_1716_579/
    
    Change-Id: I27c2badb720e56934878320906219ee7ae45f765

Author: preetham-singh