router: trace mirrored requests (#10327)

Signed-off-by: Kuat Yessenov <kuat@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 301a7a4059189c9073a31e42886a1580737165b8

envoy/api/v2/route/route_components.proto

@@ -593,6 +593,9 @@ message RouteAction {
     // number is <= the value of the numerator N, or if the key is not present, the default
     // value, the request will be mirrored.
     core.RuntimeFractionalPercent runtime_fraction = 3;
+
+    // Determines if the trace span should be sampled. Defaults to true.
+    google.protobuf.BoolValue trace_sampled = 4;
   }
 
   // Specifies the route's hashing policy if the upstream cluster uses a hashing :ref:`load balancer

envoy/config/route/v3/route_components.proto

@@ -546,6 +546,9 @@ message RouteAction {
     // number is <= the value of the numerator N, or if the key is not present, the default
     // value, the request will be mirrored.
     core.v3.RuntimeFractionalPercent runtime_fraction = 3;
+
+    // Determines if the trace span should be sampled. Defaults to true.
+    google.protobuf.BoolValue trace_sampled = 4;
   }
 
   // Specifies the route's hashing policy if the upstream cluster uses a hashing :ref:`load balancer