Add a max grpc timeout to the echo example.

When a beginner continues with the example code to set up a streaming
service, streams will be interrupted for no apparant reason after
~14 seconds. This makes sure streams will stay open.

Author: Maarten Duijn

net/grpc/gateway/examples/echo/envoy.yaml

@@ -21,7 +21,9 @@ static_resources:
               domains: ["*"]
               routes:
               - match: { prefix: "/" }
-                route: { cluster: echo_service }
+                route:
+                  cluster: echo_service
+                  max_grpc_timeout: 0s
               cors:
                 allow_origin:
                 - "*"

net/grpc/gateway/examples/echo/tutorial.md

@@ -67,7 +67,9 @@ this:
               domains: ["*"]
               routes:
               - match: { prefix: "/" }
-                route: { cluster: echo_service }
+                route:
+                  cluster: echo_service
+                  max_grpc_timeout: 0s
           http_filters:
           - name: envoy.grpc_web
           - name: envoy.router