feat(gax): standardize mapping terminal resumable upload exceptions to ApiException

[whowes]

• Local failures (IOException, IllegalStateException, etc.) are now wrapped in UnknownException with the original exception as getCause(), matching GAX's usual convention (results in quite a few updated test assertions).
• Removed manual URL suffixes from ResumableUploadChunkCoordinator and onTimeout(); toTerminalException now appends the session URL (when available) at the future boundary.
• closePayload(@Nullable Throwable) now attaches any payload.close() failure via addSuppressed() instead of swallowing it.

[gemini-code-assist]

Code Review

This pull request refactors resumable upload error handling by removing the upload URL from RewindableStreamBuffer and centralizing exception formatting in ResumableUploadFutureImpl.toTerminalException. It also improves stream cleanup by propagating suppressed exceptions during payload closure. The review feedback highlights two important improvements: adding a null check in toTerminalException to prevent a potential NullPointerException when the input exception is null, and narrowing the caught exception type in closePayload from Throwable to Exception to avoid intercepting critical JVM errors.

[sonarqubecloud]

Quality Gate passed for 'gapic-generator-java-root'

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
97.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[sonarqubecloud]

Quality Gate failed for 'gapic-generator-java-root'

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud