feat(AM-6688): make kubeslice-dns as default dns server

[rahulsawra98]

No description provided.

[rahulsawra98]

`k exec -it iperf-sleep-58c647f867-5k2hl -c iperf -n frontend -- sh
/ $ iperf -c iperf-server.frontend.svc.slice.local -p 5201 -i 1;

Client connecting to iperf-server.frontend.svc.slice.local, TCP port 5201
TCP window size: 16.0 KByte (default)

[ 1] local 10.194.16.3 port 44894 connected with 10.194.0.3 port 5201
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-1.00 sec 3.75 MBytes 31.5 Mbits/sec
[ 1] 1.00-2.00 sec 3.88 MBytes 32.5 Mbits/sec
[ 1] 2.00-3.00 sec 3.38 MBytes 28.3 Mbits/sec
[ 1] 3.00-4.00 sec 3.00 MBytes 25.2 Mbits/sec
[ 1] 4.00-5.00 sec 3.88 MBytes 32.5 Mbits/sec
[ 1] 5.00-6.00 sec 2.75 MBytes 23.1 Mbits/sec
[ 1] 6.00-7.00 sec 3.38 MBytes 28.3 Mbits/sec
[ 1] 7.00-8.00 sec 3.38 MBytes 28.3 Mbits/sec
[ 1] 8.00-9.00 sec 3.75 MBytes 31.5 Mbits/sec
[ 1] 9.00-10.00 sec 3.12 MBytes 26.2 Mbits/sec
[ 1] 10.00-10.54 sec 128 KBytes 1.93 Mbits/sec
[ 1] 0.00-10.54 sec 34.4 MBytes 27.3 Mbits/sec
`