ref(android): Support updates to nav state across multiple SentryNavEffect instances

[0xadam-brown]

📜 Description

PR allows separate SentryNavEffect instances to overlap during Activity transitions without stale cleanup clobbering the active observer.

💡 Motivation and Context

addresses: JAVA-274

💚 How did you test it?

• Unit tests
• Had my clanker use the new Nav3 sample app tab introduced in this PR to verify that nav data was interleaved and garbled when switching between Activity <> SentryNavEffect pairs prior to this PR, and fixed after.

📝 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

• Remove the @ApiStatus.Internal annotations from SentryNavEffect, SentryNavOptions, RouteNameExtractor, and RouteArgumentsExtractor once we're ready to release publicly + add an appropriate CHANGELOG entry + publish the module via craft (link).

#skip-changelog

[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.59.0 (1)	release

⚙️ sentry-android Build Distribution Settings