Fix https://github.com/grpc/grpc/issues/36367.
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Closes#36382
COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/36382 from yijiem:fix-example-cmake 54521e87a1e04496642423bfa8b6586063d848b6
PiperOrigin-RevId: 625469934
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