stats: use re2 for prometheus metrics sanitization. (#18110)
stats: use re2 for prometheus metrics sanitization. (#18110)

Signed-off-by: Takeshi Yoneda <72d3043deb9ea484d21ffcca03f662fa81cbe321@tetrate.io>
envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy,lyft/envoy,envoyproxy/envoy,envoyproxy/envoy