[Test Gap] Test the combination of fdb flush, swssconfig fdb and interface flap

[ZhaohuiS]

Description

test_configurable_drop_counters may cause orchagent crash during unshutdown interface/flush fdb/remove static fdb with swssconfig these operations.
Issue reported here: sonic-net/sonic-buildimage#11046
We can cover these scenarios in a new test case to test the combination of fdb flush, swssconfig fdb and interface flap.

Steps to reproduce the issue:
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Describe the results you received:

Describe the results you expected:

Additional information you deem important:

**Output of `show version`:**

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**Attach debug file `sudo generate_dump`:**

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