docs: Warn about sendDefaultPii removal

[adinauer]

📜 Description

Add a prominent warning to the existing data collection changelog entry that sendDefaultPii will be removed in the next major SDK version.

The warning directs customers to migrate to dataCollection before upgrading while retaining the explanation of current compatibility behavior.

💡 Motivation and Context

Customers using sendDefaultPii need a visible advance notice of its planned removal and a clear migration path.

💚 How did you test it?

• Ran ./gradlew spotlessApply apiDump
• Ran git diff --check

📝 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.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.

🔮 Next steps

None.

#skip-changelog

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.57.0 (1)	release

⚙️ sentry-android Build Distribution Settings