[P4_Symbolic] Add packet_synthesizer.

[VSuryaprasad-HCL]

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

Build Result:
/sonic/src/sonic-p4rt/sonic-pins$ bazel build $BAZEL_BUILD_OPTS ...
INFO: Analyzed 568 targets (153 packages loaded, 21484 targets configured).
INFO: Found 568 targets...
INFO: Elapsed time: 88.491s, Critical Path: 23.14s
INFO: 1 process: 1 internal.
INFO: Build completed successfully, 1 total action

Test Result:
/sonic/src/sonic-p4rt/sonic-pins$ bazel test $BAZEL_BUILD_OPTS --cache_test_results=no ...
INFO: Analyzed 568 targets (0 packages loaded, 340 targets configured).
INFO: Found 384 targets and 184 test targets...
INFO: Elapsed time: 180.439s, Critical Path: 116.99s
INFO: 238 processes: 277 linux-sandbox, 18 local.
INFO: Build completed successfully, 238 total actions
//gutil:collections_test PASSED in 0.5s
//gutil:io_test PASSED in 0.5s
//gutil:proto_matchers_test PASSED in 0.6s
//gutil:proto_ordering_test PASSED in 0.6s
//gutil:proto_test PASSED in 0.5s
//gutil:status_matchers_test PASSED in 0.5s
//gutil:test_artifact_writer_test PASSED in 0.6s
//gutil:testing_test PASSED in 0.8s
//gutil:timer_test PASSED in 5.1s
//gutil:version_test PASSED in 1.4s
//sai_p4/instantiations/google:clos_stage_test PASSED in 0.5s
//sai_p4/instantiations/google:fabric_border_router_p4info_up_to_date_test PASSED in 0.0s
//sai_p4/instantiations/google:middleblock_p4info_up_to_date_test PASSED in 0.1s
//sai_p4/instantiations/google:sai_nonstandard_platforms_build_test PASSED in 0.1s
//sai_p4/instantiations/google:sai_nonstandard_platforms_cc_test PASSED in 0.8s
//sai_p4/instantiations/google:sai_p4info_fetcher_test PASSED in 0.8s
//sai_p4/instantiations/google:sai_p4info_test PASSED in 1.1s
//sai_p4/instantiations/google:sai_pd_proto_test PASSED in 0.3s
//sai_p4/instantiations/google:sai_pd_util_test PASSED in 0.6s
//sai_p4/instantiations/google:tor_p4info_up_to_date_test PASSED in 0.1s
//sai_p4/instantiations/google:union_p4info_up_to_date_test PASSED in 0.1s
//sai_p4/instantiations/google:wbb_p4info_up_to_date_test PASSED in 0.0s
//sai_p4/instantiations/google/test_tools:table_entry_generator_helper_test PASSED in 14.4s
//sai_p4/instantiations/google/test_tools:test_entries_test PASSED in 0.9s
//sai_p4/instantiations/google/tests:p4_fuzzer_integration_test PASSED in 3.8s
//sai_p4/tools:p4info_tools_test PASSED in 0.7s
//sai_p4/tools:packetio_tools_test PASSED in 0.9s
//thinkit:bazel_test_environment_test PASSED in 0.7s
//thinkit:generic_testbed_test PASSED in 0.9s
//thinkit:mock_control_device_test PASSED in 0.6s
//thinkit:mock_generic_testbed_test PASSED in 0.8s
//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 0.9s
//sai_p4/instantiations/google/tests:p4_constraints_integration_test PASSED in 0.9s
Stats over 5 runs: max = 0.9s, min = 0.7s, avg = 0.8s, dev = 0.1s
//sai_p4/instantiations/google/test_tools:table_entry_generator_test PASSED in 44.6s
Stats over 50 runs: max = 44.6s, min = 0.8s, avg = 5.3s, dev = 12.8s

Executed 184 out of 184 tests: 184 tests pass.
INFO: Build completed successfully, 238 total actions

[mssonicbld]

/azp run

[azure-pipelines]

No pipelines are associated with this pull request.

[VSuryaprasad-HCL]

Co-authored-by: kheradmandG kheradmand@google.com