### Why I did it
Fix the issue detected by[ TestStaticMgmtPortIP::test_dynamic_dns_not_working_when_static_ip_configured ](https://github.com/sonic-net/sonic-mgmt/blob/master/tests/dns/static_dns/test_static_dns.py#L105C9-L105C63) test.
### How I did it
Query MGMT interface configuration. Do not apply dynamic DNS configuration when MGMT interface has static IP address.
#### How to verify it
Run `tests/dns/static_dns/test_static_dns.py` sonic-mgmt tests.
- Why I did it
Add support for static DNS configuration. According to sonic-net/SONiC#1262 HLD.
- How I did it
Add a new resolv-config.service that is responsible for transferring configuration from Config DB into /etc/resolv.conf file that is consumed by various subsystems in Linux to resolve domain names into IP addresses.
- How to verify it
Run the image compilation. Each component related to the static DNS feature is covered with the unit tests.
Run sonic-mgmt tests. Static DNS feature will be covered with the system tests.
Install the image and run manual tests.
