Move integrations registration to background during init

[stefanosiano]

📜 Description

moved several integrations to the background to reduce main thread usage on SDK init:
-AnrIntegration
-PhoneStateBreadcrumbsIntegration
-SystemEventsBreadcrumbsIntegration
-TempSensorBreadcrumbsIntegration

💡 Motivation and Context

Relates to #2222
It continues the work done on #3036
Fixes #3040

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code.
• 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.
• 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

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	368.22 ms	475.32 ms	107.10 ms
Size	1.72 MiB	2.29 MiB	579.28 KiB

Baseline results on branch: fix/reduce-io-init

Startup times

Revision	Plain	With Sentry	Diff
077a103	410.41 ms	464.64 ms	54.24 ms
5295259	376.14 ms	448.89 ms	72.75 ms
644ca6a	448.52 ms	547.22 ms	98.70 ms
2462226	400.98 ms	477.18 ms	76.20 ms

App size

Revision	Plain	With Sentry	Diff
077a103	1.72 MiB	2.29 MiB	578.27 KiB
5295259	1.72 MiB	2.29 MiB	577.94 KiB
644ca6a	1.72 MiB	2.29 MiB	578.27 KiB
2462226	1.72 MiB	2.29 MiB	578.43 KiB

Previous results on branch: fix/integrations-background-init

Startup times

Revision	Plain	With Sentry	Diff
7f37052	427.09 ms	507.41 ms	80.32 ms

App size

Revision	Plain	With Sentry	Diff
7f37052	1.72 MiB	2.29 MiB	578.73 KiB

[markushi]

Looking good, this will be a great step forward!
Similar to https://github.com/getsentry/sentry-java/pull/3036/files#r1393877541 I think we need to ensure thread safety within the Integrations, as different threads may modify the state at the same time.

[markushi]

LGTM! In case we want to move more integrations to the background thread, we could think about having some base class integration, which takes care of thread safe start() and close().
Nice job adapting the tests! 💯