perf(connectivity): Have only one NetworkCallback active at a time

[romtsn]

📜 Description

• Have only single NetworkCallback registered at a time
  • Multi-cast it to the internal child NetworkCallbacks (NetworkBreadcrumbsIntegration)
• Remove executor in NetworkBreadcrumbsIntegration since we just add a callback to the list now instead of doing any IPC
• While testing it I noticed replay wasn't always catching network_available breadcrumb due to timing issues, so I special-cased it in this PR too

Event example: https://sentry-sdks.sentry.io/issues/6560149804/events/960094050aa341cca6ac9d0c175f699e/
Replay example: https://sentry-sdks.sentry.io/explore/replays/fff819393dd44cfa9a06b54255664529

💡 Motivation and Context

Less IPC

💚 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

[romtsn]

one caveat: This now will not emit AVAILABLE and CAPABILITIES_CHANGED callbacks immediately after registration as opposed to calling ConnectivityManager.registerDefaultNetworkCallback.

But I think it's fine and how it should be - previously any event would always start with NETWORK_AVAILABLE breadcrumb, which could have been misleading, now we're actually adding breadcrumbs whenever there's a change.

[romtsn]

kind of unrelated to this PR, but I noticed that we also submit a task even if the status was DISCONNECTED, which was unnecessary since we'd anyway bail out in the submitted task itself.

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	471.84 ms	493.10 ms	21.26 ms
Size	1.58 MiB	2.09 MiB	520.98 KiB

Baseline results on branch: rz/fix/diff-battery-crumbs

Startup times

Revision	Plain	With Sentry	Diff
b0bed47	400.72 ms	441.62 ms	40.90 ms
4522edb	390.10 ms	421.50 ms	31.40 ms
551ddda	414.94 ms	476.12 ms	61.19 ms

App size

Revision	Plain	With Sentry	Diff
b0bed47	1.58 MiB	2.09 MiB	520.80 KiB
4522edb	1.58 MiB	2.09 MiB	520.79 KiB
551ddda	1.58 MiB	2.09 MiB	520.78 KiB

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

Startup times

Revision	Plain	With Sentry	Diff
c2f723e	382.31 ms	432.96 ms	50.65 ms

App size

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