RUM-8198 - Support custom view instrumentation types for cross-platform SDKs

[hamorillo]

What does this PR do?

Enables cross-platform SDKs (Flutter, React Native, Unity, etc.) to report custom view instrumentation types via the _dd.instrumentation_type attribute. Refactors internal ViewScopeInstrumentationType from enum to sealed interface for type safety while maintaining backward compatibility.

Motivation

Cross-platform SDKs need to report their specific navigation patterns in RUM telemetry to accurately track how views are instrumented. The previous enum-only approach couldn't accommodate arbitrary framework types like "flutter_navigator" or "react_native_navigator" without losing type safety.

Additional Notes

Sample app includes test fragment demonstrating cross-platform instrumentation types, those types are only for testing. Those are not real values.

Note: When testing this, remember that the sampling rate may drop some events. You can modify the specific ViewEnded sample rate and increase the Telemetry sample rate if necessary. In the sample app, it is already set to 100%.

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)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 34.78261% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 70.91%. Comparing base (39d8b4a) to head (eb90aa0).
⚠️ Report is 4 commits behind head on develop.

Files with missing lines	Patch %	Lines
...nternal/attributes/ViewScopeInstrumentationType.kt	0.00%	10 Missing ⚠️
.../android/rum/internal/domain/scope/RumViewScope.kt	0.00%	1 Missing and 3 partials ⚠️
.../kotlin/com/datadog/android/compose/Navigation3.kt	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3167      +/-   ##
===========================================
- Coverage    70.96%   70.91%   -0.05%     
===========================================
  Files          912      912              
  Lines        33548    33557       +9     
  Branches      5640     5642       +2     
===========================================
- Hits         23804    23794      -10     
- Misses        8173     8187      +14     
- Partials      1571     1576       +5     

Files with missing lines	Coverage Δ
...d/rum/internal/metric/ViewEndedMetricDispatcher.kt	96.83% <100.00%> (+5.65%)	⬆️
...droid/rum/tracking/ActivityViewTrackingStrategy.kt	85.45% <100.00%> (-1.82%)	⬇️
...droid/rum/tracking/FragmentViewTrackingStrategy.kt	85.71% <100.00%> (ø)
...oid/rum/tracking/NavigationViewTrackingStrategy.kt	86.96% <100.00%> (ø)
...roid/compose/internal/ComposeNavigationObserver.kt	90.48% <100.00%> (ø)
.../kotlin/com/datadog/android/compose/Navigation3.kt	13.79% <0.00%> (+0.31%)	⬆️
.../android/rum/internal/domain/scope/RumViewScope.kt	93.72% <0.00%> (-1.03%)	⬇️
...nternal/attributes/ViewScopeInstrumentationType.kt	0.00% <0.00%> (ø)

... and 36 files with indirect coverage changes

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[hamorillo]

/merge

[gh-worker-devflow-routing-ef8351]

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2026-02-05 10:32:49 UTC ℹ️ Start processing command /merge

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2026-02-05 10:32:56 UTC ℹ️ MergeQueue: waiting for PR to be ready

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2026-02-05 11:17:19 UTC ℹ️ MergeQueue: merge request added to the queue

The expected merge time in develop is approximately 1h (p90).

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2026-02-05 11:53:51 UTC ❌ MergeQueue: The checks failed on this merge request

Tests failed on this commit bc84455:

• dd-gitlab/test:tools

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