fix(replay): Fix network detail response body size being unknown for gzip-compressed responses

[romtsn]

📜 Description

For gzip-compressed responses, OkHttp strips the Content-Length header during transparent decompression, so response.body.contentLength() returns -1. This caused NetworkRequestData.responseBodySize to always be unknown for replay network details on such responses.

This PR adds originalByteCount to NetworkBody, populated from the actual byte array length in NetworkBodyParser.fromBytes. NetworkDetailCaptureUtils.createRequestOrResponseInternal now uses this as a fallback when the passed bodySize is null or -1.

The fix piggybacks on the existing peekBody call — no additional network I/O. For responses larger than the peek limit (MAX_NETWORK_BODY_SIZE), the capped byte count is reported (lower bound) instead of unknown.

Example replay: https://sentry-sdks.sentry.io/explore/replays/95bf32448ef94fafb41b5164ccde5d19

💡 Motivation and Context

Session replay network details show response body size. For gzip-compressed HTTP responses (common for JSON APIs), OkHttp's transparent decompression strips Content-Length, making the size always unknown (-1). The Sentry UI shows "It is possible the network transfer size is smaller due to compression", so reporting the decompressed size is the correct behavior.

Fixes SDK-1006

💚 How did you test it?

• Added unit tests for NetworkBodyParser covering originalByteCount for both truncated and non-truncated bodies
• Added unit tests for NetworkDetailCaptureUtils covering the bodySize fallback logic (unknown → uses byte count, explicit → preserved, body capture off → unchanged)
• Verified existing tests pass

📝 Checklist

• I added GH Issue ID & Linear ID
• 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

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.44.1 (1)	release

⚙️ sentry-android Build Distribution Settings

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	314.33 ms	376.04 ms	61.71 ms
Size	0 B	0 B	0 B

Baseline results on branch: main

Startup times

Revision	Plain	With Sentry	Diff
18c0bc2	306.73 ms	349.77 ms	43.03 ms
0eaac1e	316.82 ms	357.34 ms	40.52 ms
d15471f	303.49 ms	439.08 ms	135.59 ms
fc5ccaf	276.52 ms	370.46 ms	93.93 ms
e2dce0b	308.96 ms	360.10 ms	51.14 ms
5b1a06b	352.27 ms	413.70 ms	61.43 ms
37ec571	366.04 ms	424.28 ms	58.23 ms
9fbb112	361.43 ms	427.57 ms	66.14 ms
bbc35bb	324.88 ms	425.73 ms	100.85 ms
ff8eea4	313.42 ms	337.08 ms	23.66 ms

App size

Revision	Plain	With Sentry	Diff
18c0bc2	1.58 MiB	2.13 MiB	557.33 KiB
0eaac1e	1.58 MiB	2.19 MiB	619.17 KiB
d15471f	1.58 MiB	2.13 MiB	559.54 KiB
fc5ccaf	1.58 MiB	2.13 MiB	557.54 KiB
e2dce0b	0 B	0 B	0 B
5b1a06b	0 B	0 B	0 B
37ec571	0 B	0 B	0 B
9fbb112	1.58 MiB	2.11 MiB	539.18 KiB
bbc35bb	1.58 MiB	2.12 MiB	553.01 KiB
ff8eea4	1.58 MiB	2.28 MiB	718.64 KiB

Previous results on branch: rz/fix/replay-network-body-size

Startup times

Revision	Plain	With Sentry	Diff
614bb16	313.93 ms	353.38 ms	39.44 ms

App size

Revision	Plain	With Sentry	Diff
614bb16	0 B	0 B	0 B

[linear-code]

SDK-1006