Convert OpenTelemetryRumBuilder to kotlin

[fractalwrench]

Goal

Converts OpenTelemetryRumBuilder from Java to Kotlin. I've tried to retain the API as close as possible to the existing API dump, and have avoided converting symbols such as BiFunction to their Kotlin equivalents for now (although I think this is worth pursuing in future).

I've mostly relied on OpenTelemetryRumBuilderTest to alert of any breaking changes this might have introduced.

[codecov]

Codecov Report

❌ Patch coverage is 81.15942% with 39 lines in your changes missing coverage. Please review.
✅ Project coverage is 63.26%. Comparing base (3d967af) to head (afbad20).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...o/opentelemetry/android/OpenTelemetryRumBuilder.kt	81.15%	37 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1372      +/-   ##
==========================================
- Coverage   64.18%   63.26%   -0.92%     
==========================================
  Files         158      158              
  Lines        3110     3125      +15     
  Branches      320      319       -1     
==========================================
- Hits         1996     1977      -19     
- Misses       1020     1053      +33     
- Partials       94       95       +1     

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[LikeTheSalad]

Thank you!