[submodule]: Advance sonic-utilities. (#4316)

Commits on Mar 24, 2020
- [config] Add sflow to _reset_failed_services (#850) 04648f5
- [fwutil]: Use overlay driver when mounting next image filesystem (#825) 668c116
- Fix for adding L3 interface to Vlan group (#826) 6e3679b
- [fwutil]: Fix component table layout. (#831) 30adcbd 

Signed-off-by: Nazarii Hnydyn <nazariig@mellanox.com>