[Dvaas]: Create function to retag packets and update the tag for entire PacketTestVector.

[VSuryaprasad-HCL]

Keyword Check:

~/pins_upstream/sonic-buildimage/src/sonic-p4rt/sonic-pins/dvaas$ ~/tools/keyword_checks.sh .
Keyword check Passed.

Build result:

sonic/src/sonic-p4rt/sonic-pins$ bazel build $BAZEL_BUILD_OPTS ...
INFO: Analyzed 579 targets (0 packages loaded, 0 targets configured).
INFO: Found 579 targets...
INFO: Elapsed time: 23.757s, Critical Path: 20.22s
INFO: 6 processes: 2 internal, 4 linux-sandbox.
INFO: Build completed successfully, 6 total actions

Test result:

/sonic/src/sonic-p4rt/sonic-pins$ bazel test $BAZEL_BUILD_OPTS --cache_test_results=no ...
INFO: Analyzed 582 targets (0 packages loaded, 6 targets configured).
INFO: Found 390 targets and 192 test targets...
INFO: Elapsed time: 186.155s, Critical Path: 114.79s
INFO: 246 processes: 289 linux-sandbox, 18 local.
INFO: Build completed successfully, 246 total actions
//dvaas:port_id_map_test                                                 PASSED in 0.5s
//dvaas:test_vector_stats_diff_test                                      PASSED in 0.0s
//dvaas:test_vector_stats_test                                           PASSED in 0.1s
//dvaas:test_vector_test                                                 PASSED in 0.6s
//dvaas:user_provided_packet_test_vector_diff_test                       PASSED in 0.1s
//dvaas:user_provided_packet_test_vector_test                            PASSED in 0.0s
//gutil:collections_test                                                 PASSED in 0.5s
//gutil:io_test                                                          PASSED in 0.6s
//gutil:proto_matchers_test                                              PASSED in 0.6s
//gutil:proto_ordering_test                                              PASSED in 0.5s
//gutil:proto_test                                                       PASSED in 0.5s
//gutil:status_matchers_test                                             PASSED in 0.5s
//gutil:test_artifact_writer_test                                        PASSED in 0.6s
//thinkit:mock_generic_testbed_test                                      PASSED in 0.7s
//thinkit:mock_mirror_testbed_test                                       PASSED in 0.7s
//thinkit:mock_ssh_client_test                                           PASSED in 0.0s
//thinkit:mock_switch_test                                               PASSED in 0.7s
//thinkit:mock_test_environment_test                                     PASSED in 0.1s
//thinkit:switch_test                                                    PASSED in 0.7s
//sai_p4/instantiations/google/tests:p4_constraints_integration_test     PASSED in 0.8s
  Stats over 5 runs: max = 0.8s, min = 0.7s, avg = 0.7s, dev = 0.1s
//sai_p4/instantiations/google/test_tools:table_entry_generator_test     PASSED in 43.8s
  Stats over 50 runs: max = 43.8s, min = 0.8s, avg = 3.0s, dev = 8.4s

Executed 192 out of 192 tests: 192 tests pass.
INFO: Build completed successfully, 246 total actions

[bibhuprasad-hcl]

@kishanps, Could you please review.
Thanks.