feat: client-side sampleRate to Android session replay

[abelonogov-ld]

Summary

• Add sampleRate to ReplayOptions, mirroring iOS SessionReplayOptions.sampleRate (probability from 0.0–1.0 that replay starts when enabled).
• Introduce SessionReplaySampling / SessionReplaySamplingSession to evaluate sampling once per enable cycle and reset on stop.
• Update SessionReplayService to separate user intent (isEnabled) from active recording (isRunning), gating collectors and capture on the latter.

Test plan

• ./gradlew :lib:testDebugUnitTest in observability-android
• Verify a session with sampleRate = 0.0 never records
• Verify a session with sampleRate = 1.0 records as before
• Merge and publish Android library before RN bridge PR that depends on this API

Made with Cursor

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Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

^{Reviewed by Cursor Bugbot for commit 9e399f7. Configure here.}

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Sampled-out replay drops identify

Medium Severity

When replay is enabled but excluded by sampleRate, identifySession returns immediately without caching the payload. That differs from the disabled path, which stores pending identify for the next start. After a later stop/start that wins sampling, recording can begin without the user context that was already identified.

 

^{Reviewed by Cursor Bugbot for commit 9e399f7. Configure here.}