[Gitar] Cleaning up stale flag: sample-feature with value true

[gitar-bot-staging[bot]]

This automated PR permanently enables the sample-feature feature flag.

Details

Triggered via https://github.com/gitarcode/launchdarkly-hello-java/issues/660#issuecomment-2468634261 by @optimus-primal[bot]

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This automated PR was generated by Gitar. View docs.

[optimus-primal[bot]]

Confirming code cleanup...🤖