test(replay): keep trigger-started recording when remote config reloads unchanged event triggers

[ioannisj]

💡 Motivation and Context

Parity check for posthog-ios#919. On iOS, every remote config load clears the event-trigger activation and stops replay, even when the trigger list is unchanged. So with a cached config, a trigger that fires right after launch starts recording and the first live /config response stops it.

Android doesn't have this bug. triggerActivatedSessionId is only set when a trigger matches and nothing on the onRemoteConfig path resets it. shouldWaitForEventTriggers only checks whether the current session was activated, so a config reload can only stop recording through the flag, master switch or sampling gates. That matches posthog-js, which also never resets activation on config.

Adds a regression test to keep it that way. Test only, no SDK change.

💚 How did you test it?

• New test remote config with unchanged event triggers keeps a trigger started recording. It starts from the cached config only, fires a trigger, then delivers the first live config and a later reload with the same triggers (same order and reordered), and asserts replay stays active for the same session id.
• I temporarily added the iOS reset-and-stop to onRemoteConfig and the test fails on the first live config, so it does catch the regression.
• ./gradlew :posthog-android:testDebugUnitTest and make checkFormat pass.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm changeset to generate a changeset file

🤖 Agent context

DRI: @ioannisj
Autonomy: Human-driven (agent-assisted)

[github-actions]

⚠️ `posthog-android` is modified but this PR has no changeset

This is informational — the PR is not blocked. Click the triangle above to collapse, or push a fix and this comment will auto-delete.

Modified in this PR but no changeset added:

• posthog-android

If this change should ship, run pnpm changeset and select a bump level.
If it isn't user-facing (refactor with no behavior change, internal tooling, generated files), no action needed.

[greptile-apps]

[Low impact] This test-only change appears safe to merge.

_{Reviews (1) · Last reviewed commit: "test(replay): keep trigger-started recor..." · Reviewed by Greptile}