perf(android): [SDK Overhead Reduction 4] Use default timezone directly

[adinauer]

PR Stack (SDK Overhead Reduction)

• perf(core): [SDK Overhead Reduction 1] Skip java.specification.version lookup on Android #5500
• perf(android): [SDK Overhead Reduction 2] Replace reflective OptionsContainer with direct subclass #5501
• perf(android): [SDK Overhead Reduction 3] Reuse SentryExecutorService for DeviceInfoUtil pre-caching #5502
• perf(android): [SDK Overhead Reduction 4] Use default timezone directly #5587
• perf(core): [SDK Overhead Reduction 5] Replace Calendar with Date in DateUtils #5589
• perf(core): [SDK Overhead Reduction 6] Reduce JsonWriter stack allocation #5591

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📜 Description

Replace Calendar.getInstance(...).getTimeZone() with TimeZone.getDefault() when collecting the Android device timezone. The locale passed to Calendar.getInstance(locale) does not affect the timezone value, so constructing a Calendar here only adds unnecessary work.

💡 Motivation and Context

Part of the SDK Overhead Reduction stack. Device context collection only needs the process default timezone. TimeZone.getDefault() is available on Android API 21 and Java 8, and avoids constructing a Calendar and reading locale configuration just to retrieve the same timezone.

💚 How did you test it?

• ./gradlew :sentry-android-core:testDebugUnitTest --tests io.sentry.android.core.DeviceInfoUtilTest — all tests pass
• ./gradlew spotlessApply apiDump — no API surface changes

📝 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

More SDK overhead reduction PRs in this stack.

⚠️ Merge this PR using a merge commit (not squash). Only the collection branch is squash-merged into main.

#skip-changelog

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.43.1 (1)	release

⚙️ sentry-android Build Distribution Settings

[github-actions]

Performance metrics 🚀

	Plain	With Sentry	Diff
Startup time	351.04 ms	416.90 ms	65.85 ms
Size	0 B	0 B	0 B