[vstest]: Fix MACsec test in the kernel 5.15

[Pterosaur]

What I did
Provide an explicit value for send_sci in the macsec vstest

Why I did it

The kernel 5.15 requires the send_sci to be true if the sci value was provided explicitly.

How I verified it

AzDevOps@test-os-u000048:/agent/_work/1/s/sonic-swss/tests$ sudo pytest --dvsname=vs test_macsec.py  --pdb
=========================================================================================== test session starts ============================================================================================
platform linux -- Python 3.8.10, pytest-4.6.2, py-1.11.0, pluggy-0.13.1
rootdir: /agent/_work/1/s/sonic-swss/tests
plugins: flaky-3.7.0
collected 4 items                                                                                                                                                                                          

test_macsec.py ....                                                                                                                                                                                  [100%]

============================================================================================= warnings summary =============================================================================================
test_macsec.py:311
  /agent/_work/1/s/sonic-swss/tests/test_macsec.py:311: PytestAssertRewriteWarning: assertion is always true, perhaps remove parentheses?
    assert(

test_macsec.py:278
  /agent/_work/1/s/sonic-swss/tests/test_macsec.py:278: PytestAssertRewriteWarning: assertion is always true, perhaps remove parentheses?
    assert(

test_macsec.py:251
  /agent/_work/1/s/sonic-swss/tests/test_macsec.py:251: PytestAssertRewriteWarning: assertion is always true, perhaps remove parentheses?
    assert(

test_macsec.py:258
  /agent/_work/1/s/sonic-swss/tests/test_macsec.py:258: PytestAssertRewriteWarning: assertion is always true, perhaps remove parentheses?
    assert(

test_macsec.py:264
  /agent/_work/1/s/sonic-swss/tests/test_macsec.py:264: PytestAssertRewriteWarning: assertion is always true, perhaps remove parentheses?
    assert(

-- Docs: https://docs.pytest.org/en/latest/warnings.html
================================================================================== 4 passed, 5 warnings in 78.32 seconds ===================================================================================

Details if related

[mssonicbld]

/azp run

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[mssonicbld]

/azp run

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