[action] [PR:9599] [advanced-reboot][dualtor] Update Loopback0 ping test: expect same count for sent and rcvd packets

[mssonicbld]

Description of PR

Summary: Currently dual tor warmboot fails w/ control plane not ready for warmboot. This is because the test expects 2 responses for every ping packet sent to Loopback. This expectation is not correct after PR #9089 is merged.

Update the testcase to now only expect 1 icmp response for every icmp packet sent to Loopback0.

Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 201911
• 202012
• 202205

Approach

What is the motivation for this PR?

Dualtor warmboot fails w/ below error:

2023-08-17 18:14:39 : Send 100 Received 100 servers->t1
2023-08-17 18:14:41 : Send 500 Received 500 t1->servers
2023-08-17 18:14:41 : Data plane state transition from partial to up (500)
2023-08-17 18:14:42 : Send 10 Received 0 ping DUT

2023-08-17 18:14:45 : --------------------------------------------------
2023-08-17 18:14:45 : Fails:
2023-08-17 18:14:45 : --------------------------------------------------
2023-08-17 18:14:45 : FAILED:dut:IO didn't come up within warm up timeout. Control plane: down, Data plane: up
2023-08-17 18:14:45 : FAILED:dut:DUT is not ready for test
2023-08-17 18:14:45 : ==================================================

How did you do it?

Updated the test to remove the earlier expectation of removing the packets that were sent by icmp_responder.

This essentially reverts part of older PR: #6968

How did you verify/test it?

Tested on a physical testbed and this test issue is not seen.
The test is now able to see the responses of ping packets:

2023-08-22 22:39:06 : Send 100 Received 100 servers->t1
2023-08-22 22:39:07 : Send 500 Received 500 t1->servers
2023-08-22 22:39:09 : Send 10 Received 10 ping DUT
2023-08-22 22:39:10 : Send 1 Received 1 arp ping
2023-08-22 22:39:12 : Send 100 Received 100 servers->t1
2023-08-22 22:39:13 : Send 500 Received 500 t1->servers
2023-08-22 22:39:15 : Send 10 Received 10 ping DUT
2023-08-22 22:39:15 : Schedule to reboot the remote switch in 10 sec
2023-08-22 22:39:15 : Wait until Control plane is down

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[mssonicbld]

Original PR: #9599