fix(replay): Backfill release, environment and SDK for replays from the previous run

[sentry-junior]

📜 Description

When the SDK starts, ReplayIntegration.finalizePreviousReplay() sends the last cached segment of the previous run's replay using PreviousReplayHint, which is Backfillable. Because of that hint, MainEventProcessor intentionally skips release, environment, dist and SDK, since the current run's values may not describe the earlier one. Nothing filled them in afterwards (there was a TODO for this), so these segments went out with no sdk, release or environment.

This change reads those values from the options persisted by PersistingOptionsObserver and sets them on the replay event before it is captured. The integration registers before Sentry.init runs notifyOptionsObservers, and both use the single-threaded SDK executor, so the persisted values still belong to the run that recorded the replay. If no SDK version was persisted, it falls back to the current options.sdkVersion, because the SDK name stays the same between runs and a replay with no SDK info is worse than one with a slightly newer version.

Persisted scope values (user, tags, contexts) are still not backfilled; I left a TODO for that.

💡 Motivation and Context

On the Sentry side, a replay gets its SDK name from any of its segments. A replay whose only segment came through this path (e.g. buffer mode, app killed or crashed, replay flushed on next launch) has no sdk.name, release or environment at all. The replay details page then can't tell which mobile platform's docs to link to and reports Unknown mobile platform in configure card: null. We could reproduce this with single-segment buffer replays from an internal Android project.

💚 How did you test it?

Added unit tests in ReplayIntegrationTest covering both the persisted-options backfill and the SDK version fallback. Both tests fail without the fix.

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.

🔮 Next steps

Backfill persisted scope values (user, tags, contexts) for previous-run replays.

via roman.

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View Junior Session [Sentry]

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.60.0 (1)	release

⚙️ sentry-android Build Distribution Settings

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[adinauer]

LGTM

[0xadam-brown]

A few quick comments for your consideration, but no blockers 👍