[202012] update sonic-utilities submodule (#9195)

Submodule update for sonic-utilties

```
48035d75 [202012] [techsupport] Techsupport Error Reporting pending fixes (#1854)
8b2ec09a Fix log_ssd_health hang issue (#1904)
ac9c4254 Fix the option missing in kernel config issue (#1888)
5cc9417a disk_check: Script updated to run good in 201811 & 201911 (#1747)
```