statsd: revert visibility to public (#12621)
statsd: revert visibility to public (#12621)

Commit Message: reverts visibility of the statd sink to public.
Risk Level: low
Testing: local build, CI

Signed-off-by: Jose Nino <ca94e32c82b10963d0ce6eadf427a615ff7d1c0b@lyft.com>
lizan/envoy,envoyproxy/envoy,lyft/envoy,lizan/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,lizan/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,lyft/envoy,lyft/envoy,lizan/envoy,lizan/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy-wasm,lyft/envoy,envoyproxy/envoy,lizan/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy,envoyproxy/envoy-wasm,envoyproxy/envoy-wasm,envoyproxy/envoy