[submodule] Update submodule sonic-host-services to the latest HEAD a…

…utomatically (#15591)

#### Why I did it
src/sonic-host-services
```
* eab4a9e - (HEAD -> master, origin/master, origin/HEAD) [hostcfgd][dns] Subscribe to DNS_NAMESERVER table to react to static DNS configuration changes. (#49) (2 days ago) [Oleksandr Ivantsiv]
```
#### How I did it
#### How to verify it
#### Description for the changelog