Update copyright

[0xnm]

What does this PR do?

This PR updates copyright in the project files: in some places it was missing, it some places it was outdated.

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• Make sure you discussed the feature or bugfix with the maintaining team in an Issue
• Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

[xgouchet]

Nice catch, Maybe we could have some static analysis job that verifies all files have a valid copyright?

[codecov-commenter]

Codecov Report

Merging #1992 (0af6e7a) into develop (18967d7) will decrease coverage by 0.10%.
Report is 8 commits behind head on develop.
The diff coverage is n/a.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1992      +/-   ##
===========================================
- Coverage    83.66%   83.57%   -0.10%     
===========================================
  Files          488      488              
  Lines        17770    17738      -32     
  Branches      2663     2658       -5     
===========================================
- Hits         14867    14823      -44     
- Misses        2178     2193      +15     
+ Partials       725      722       -3     

Files	Coverage Δ
...atadog/android/core/internal/utils/ThrowableExt.kt	100.00% <ø> (ø)
...internal/instrumentation/gestures/GesturesUtils.kt	90.91% <ø> (ø)
...nternal/tracking/OreoFragmentLifecycleCallbacks.kt	90.00% <ø> (ø)
...roid/webview/internal/rum/WebViewRumEventMapper.kt	100.00% <ø> (ø)

... and 27 files with indirect coverage changes

[0xnm]

@xgouchet Good suggestion, I created a ticket for that. Thanks for comment from @jonathanmos here, I realized that Android Studio by some reason doesn't add copyright to the new files (even though copyright is declared in the editor settings).