[Backport-202205][acl-loader] Only add default deny rule when table is L3 or L3V6 (#2796)

[lizhijianrd]

Backport #2796 to 202205 branch.

What I did

1. Update acl-loader to only add default deny rule when table is L3 or L3V6.
2. Update unittest to cover it.

How I did it

Update function deny_rule and return {} if table is not L3 or L3V6.

How to verify it

1. Update unittest and run all testcases to verify.
2. Built the package and installed on DUT to verify.

Unittest results on 202205 branch:

tests/acl_loader_test.py::TestAclLoader::test_acl_empty PASSED                                                                [  0%]
tests/acl_loader_test.py::TestAclLoader::test_valid PASSED                                                                    [  0%]
tests/acl_loader_test.py::TestAclLoader::test_invalid PASSED                                                                  [  0%]
tests/acl_loader_test.py::TestAclLoader::test_validate_mirror_action PASSED                                                   [  1%]
tests/acl_loader_test.py::TestAclLoader::test_vlan_id_translation PASSED                                                      [  1%]
tests/acl_loader_test.py::TestAclLoader::test_vlan_id_lower_bound PASSED                                                      [  1%]
tests/acl_loader_test.py::TestAclLoader::test_vlan_id_upper_bound PASSED                                                      [  1%]
tests/acl_loader_test.py::TestAclLoader::test_vlan_id_not_a_number PASSED                                                     [  1%]
tests/acl_loader_test.py::TestAclLoader::test_ethertype_translation PASSED                                                    [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_translation PASSED                                                         [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmpv6_translation PASSED                                                       [  1%]
tests/acl_loader_test.py::TestAclLoader::test_ingress_default_deny_rule PASSED                                                [  1%]
tests/acl_loader_test.py::TestAclLoader::test_egress_no_default_deny_rule PASSED                                              [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_type_lower_bound PASSED                                                    [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_type_upper_bound PASSED                                                    [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_type_not_a_number PASSED                                                   [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_code_lower_bound PASSED                                                    [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_code_upper_bound PASSED                                                    [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_code_not_a_number PASSED                                                   [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_fields_with_non_icmp_protocol PASSED                                       [  1%]
tests/acl_loader_test.py::TestAclLoader::test_icmp_fields_with_non_tcp_protocol PASSED                                        [  1%]
tests/acl_loader_test.py::TestAclLoader::test_incremental_update PASSED                                                       [  1%]

----------- coverage: platform linux, python 3.9.2-final-0 -----------
Name                                                   Stmts   Miss Branch BrPart  Cover
----------------------------------------------------------------------------------------
acl_loader/__init__.py                                     0      0      0      0   100%
acl_loader/main.py                                       638    167    284     49    69%
...
----------------------------------------------------------------------------------------
TOTAL                                                  38668  11513  13845   1937    67%
Coverage HTML written to dir htmlcov
Coverage XML written to file coverage.xml

====================================================== short test summary info ======================================================
FAILED tests/disk_check_test.py::TestDiskCheck::test_readonly - assert 1 == 0
FAILED tests/drops_group_test.py::TestDropCounters::test_show_counts - AssertionError: assert ('    IFACE    STATE    RX_ERR    RX...
FAILED tests/drops_group_test.py::TestDropCounters::test_show_counts_with_group - AssertionError: assert ('\n'\n '          DEVICE...
FAILED tests/drops_group_test.py::TestDropCounters::test_show_counts_with_type - AssertionError: assert ('    IFACE    STATE    RX...
================================ 4 failed, 2044 passed, 3 skipped, 19 warnings in 508.01s (0:08:28) =================================