License update - Batch 21

[mossmana]

Updates the license headers for:

1. packages/devtools_app/lib/src/screens/network/constants.dart
2. packages/devtools_app/lib/src/screens/network/har_builder.dart
3. packages/devtools_app/lib/src/screens/network/har_data_entry.dart
4. packages/devtools_app/lib/src/screens/network/har_network_data.dart
5. packages/devtools_app/lib/src/screens/network/network_controller.dart
6. packages/devtools_app/lib/src/screens/network/network_model.dart
7. packages/devtools_app/lib/src/screens/network/network_request_inspector.dart
8. packages/devtools_app/lib/src/screens/network/network_request_inspector_views.dart
9. packages/devtools_app/lib/src/screens/network/network_screen.dart
10. packages/devtools_app/lib/src/screens/network/network_service.dart
11. packages/devtools_app/test/screens/network/har_network_test.dart
12. packages/devtools_app/test/screens/network/network_controller_test.dart
13. packages/devtools_app/test/screens/network/network_model_test.dart
14. packages/devtools_app/test/screens/network/network_profiler_test.dart
15. packages/devtools_app/test/screens/network/network_request_inspector_test.dart
16. packages/devtools_app/test/screens/network/network_screen_test.dart
17. packages/devtools_app/test/screens/network/network_table_test.dart
18. packages/devtools_app/test/screens/network/utils/network_test_utils.dart

#8216

Pre-launch Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• I read the [Flutter Style Guide] recently, and have followed its advice.
• I signed the [CLA].
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or there is a reason for not adding tests.

[kenzieschmoll]

Can we hold off on this PR for a few days? We have a network page related PR (#8332) that a contributor has been working on for a few months. This PR should be landing soon and it adds some new files so it would be good to make sure the license update runs on those new files.