fix: Session replay crash when writing the replay

[brustolin]

📜 Description

Checks the status of the asset writer before using it.

💡 Motivation and Context

closes #4185

💚 How did you test it?

Sample and unit test

📝 Checklist

You have to check all boxes before merging:

• 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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.365%. Comparing base (f1b97be) to head (254224c).

Additional details and impacted files

@@              Coverage Diff              @@
##              main     #4186       +/-   ##
=============================================
- Coverage   91.370%   91.365%   -0.006%     
=============================================
  Files          606       606               
  Lines        48356     48373       +17     
  Branches     17455     17457        +2     
=============================================
+ Hits         44183     44196       +13     
- Misses        4082      4085        +3     
- Partials        91        92        +1     

Files	Coverage Δ
...egrations/SessionReplay/SentryOnDemandReplay.swift	90.178% <100.000%> (+0.270%)	⬆️
...ions/SessionReplay/SentryOnDemandReplayTests.swift	97.938% <100.000%> (+0.377%)	⬆️

... and 6 files with indirect coverage changes

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[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	1230.67 ms	1248.94 ms	18.27 ms
Size	21.58 KiB	682.03 KiB	660.45 KiB

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
db533ee	1228.96 ms	1248.23 ms	19.28 ms
8001609	1217.87 ms	1231.31 ms	13.44 ms
83d84d7	1244.92 ms	1253.34 ms	8.42 ms
5f8ee7a	1249.48 ms	1252.20 ms	2.72 ms
bbcbaff	1216.82 ms	1242.34 ms	25.52 ms
e2abb0d	1235.08 ms	1257.00 ms	21.92 ms
06bac56	1205.76 ms	1247.83 ms	42.07 ms
725565a	1234.59 ms	1250.02 ms	15.43 ms
62c15d4	1235.30 ms	1260.82 ms	25.52 ms
02e1163	1199.86 ms	1211.78 ms	11.92 ms

App size

Revision	Plain	With Sentry	Diff
db533ee	21.58 KiB	547.02 KiB	525.44 KiB
8001609	21.58 KiB	670.46 KiB	648.88 KiB
83d84d7	22.84 KiB	402.56 KiB	379.72 KiB
5f8ee7a	22.85 KiB	411.93 KiB	389.08 KiB
bbcbaff	22.85 KiB	414.09 KiB	391.24 KiB
e2abb0d	20.76 KiB	434.72 KiB	413.96 KiB
06bac56	22.84 KiB	403.23 KiB	380.38 KiB
725565a	20.76 KiB	426.11 KiB	405.35 KiB
62c15d4	22.85 KiB	411.14 KiB	388.29 KiB
02e1163	21.58 KiB	418.82 KiB	397.24 KiB