IP_decap test and FIB tests doesn't work for non-contiguous ports.

The files IP_decap_test.py and fib_test.py takes the source port range from 0 to 32 . If the ports are non-contiguous , the test fails.

sonic-mgmt/ansible/roles/test/files/ptftests/IP_decap_test.py

    if self.test_params['testbed_type'] == 't1' or self.test_params['testbed_type'] == 't1-lag':
        self.src_ports = range(0, 32)

sonic-mgmt/ansible/roles/test/files/ptftests/IP_decap_test.py

    if self.test_params['testbed_type'] == 't1' or self.test_params['testbed_type'] == 't1-lag':
        self.src_ports = range(0, 32)