[copp] Update the way copp config is applied in test_copp

[AndriiLozovyi]

Signed-off-by: Andrii-Yosafat Lozovyi andrii-yosafatx.lozovyi@intel.com

Description of PR

Summary: test_copp.py started to fail after SONiC.master.43510-dirty-20211014.091725 because new COPP config wasn't applied on DUT, this happened due to recent PR - 8969 that binded copp-config.service to sonic.target.
In order to apply new COPP config copp_cfg.j2 file should be edited. This PR will updated the way COPP config is applied in test_copp.py.
Fixes # (issue)

Type of change

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

Back port request

• 201911

Approach

What is the motivation for this PR?

Update the way COPP config is applied in TC due to recent changes in - 8969

How did you do it?

How did you verify/test it?

Run test_copp.py on SONiC.master.43510-dirty-20211014.091725

copp/test_copp.py::TestCOPP::test_policer[ARP] PASSED                                                                                                             
copp/test_copp.py::TestCOPP::test_policer[IP2ME] PASSED                                                                                                           
copp/test_copp.py::TestCOPP::test_policer[SNMP] PASSED                                                                                                            
copp/test_copp.py::TestCOPP::test_policer[SSH] PASSED                                                                                                             
copp/test_copp.py::TestCOPP::test_no_policer[BGP] PASSED                                                                                                          
copp/test_copp.py::TestCOPP::test_no_policer[DHCP] PASSED                                                                                                         
copp/test_copp.py::TestCOPP::test_no_policer[LACP] PASSED                                                                                                         
copp/test_copp.py::TestCOPP::test_no_policer[LLDP] PASSED                                                                                                         
copp/test_copp.py::TestCOPP::test_no_policer[UDLD] PASSED

Any platform specific information?

SONiC Software Version: SONiC.master.43510-dirty-20211014.091725
Distribution: Debian 10.11
Kernel: 4.19.0-12-2-amd64
Build commit: b9366f3f8
Build date: Thu Oct 14 15:11:38 UTC 2021
Built by: AzDevOps@sonic-build-workers-000SG3
Platform: x86_64-arista_7170_64c
HwSKU: Arista-7170-64C

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

Documentation

[AndriiLozovyi]

@yxieca Could you please take a look ?