[hln33]

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Issue Link, if available

Reverts #819 (commit e512588a8273c225e931aa3cc6e86b5b0ceb4c22). This restores the telemetry-exporter state from #809.

Description

This PR removes the @Experimental annotation and its import from 27 public types in the telemetry-exporter module. It also removes the "(preview)" heading and the Preview API note from telemetry-exporter/README.md.

The diff is the exact inverse of the #819 squash commit. All 28 files are under telemetry-exporter/. Runtime implementations, API signatures, and Maven versions are unchanged. No commit merged after #819 touches telemetry-exporter/, so the revert applied without conflicts.

No package publication, deployment, merge, or auto-merge is requested.

Demo/Screenshots

Not applicable. This is a revert of stability markers and documentation.

Checklist

• I have filled out every section of the PR template
• I have thoroughly tested this change

Testing

Validated locally with Maven on top of main at 541ea406.

• Confirmed the committed diff is byte-identical to the inverse of e512588a (28 files, +1/-69).
• mvn -B -pl telemetry-exporter -am clean verify: BUILD SUCCESS. 246 tests ran in telemetry-exporter; 0 failures.
• mvn -B spotless:check: passed.

Unit Tests

Existing unit tests are used. No new test is added.

Integration Tests

Existing tests are used. Cloud tests are not enabled.

Examples

No new example. Runtime implementations and API signatures are unchanged.

[github-actions]

Codex AI review

No actionable findings. Changes are limited to removing experimental annotations and preview documentation; runtime logic and API signatures remain unchanged. Tests were not run under the read-only review constraints.

Reviewed commit df27a1d77219dae7933bf20b9128371bf73b29a8. Workflow run