[submodule] sonic-utilities submodule update (#14937)

#### Why I did it
sonic-utilities submodule update for 202012

```
* d20fc3c8 2023-04-07 | [202012][DBMigrator] Update db_migrator to support EdgeZoneAggregator Buffer Config for T0s (#2768) (HEAD, origin/202012) [Dev Ojha]
* 322a74dd 2023-03-27 | Resolved rc!=0 problem by replacing fgrep with awk. Added ipv4 filtering to get only v4 peers in case of show ip bgp neighbors (#2743) [saurabhab]
```

##### Work item tracking
- Microsoft ADO **(number only)**: 20782336