refactor(lifecycle): Use single lifecycle observer

[romtsn]

📜 Description

• Refactors the integrations that subscribe for Lifecycle updates
  • There's only one callback registered in AppState now, upon initializing the SDK
  • The callback then is multi-casted to the internal listeners
  • It maintains the old behaviour where addObserver call would catch the new observer up to the current lifecycle state
• Simplified SystemEventBreadcrumbsIntegration by removing a few unnecessary locks and calling unregisterReceiver from a background thread because it also does an IPC call

💡 Motivation and Context

easier to maintain SDK

💚 How did you test it?

manually + automated

📝 Checklist

• 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.

🔮 Next steps

Use this new lifecycle approach to register/unregister NetworkCallback

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	381.06 ms	407.08 ms	26.02 ms
Size	1.58 MiB	2.09 MiB	521.14 KiB

Baseline results on branch: rz/perf/single-network-callback

Startup times

Revision	Plain	With Sentry	Diff
5993034	471.84 ms	493.10 ms	21.26 ms
c2f723e	382.31 ms	432.96 ms	50.65 ms

App size

Revision	Plain	With Sentry	Diff
5993034	1.58 MiB	2.09 MiB	520.98 KiB
c2f723e	1.58 MiB	2.09 MiB	520.98 KiB

Previous results on branch: rz/perf/single-lifecycle-observer

Startup times

Revision	Plain	With Sentry	Diff
6fd675a	403.43 ms	446.55 ms	43.13 ms

App size

Revision	Plain	With Sentry	Diff
6fd675a	1.58 MiB	2.09 MiB	521.12 KiB