fuzz: fixes oss-fuzz: 9621 (#3988)

The issue is due to on the crash of Envoy::Network::Utility::getAddressWithPort because of the invalid port_value. Added max constraint validate rule to the port_value field.

Risk Level: Low

Testing: Tested unit tests (bazel test //test/server/config_validation:config_fuzz_test), built and ran fuzzers with oss-fuzz.

Signed-off-by: Anirudh M <m.anirudh18@gmail.com>

Mirrored from https://github.com/envoyproxy/envoy @ 7d61b00171fb3cc349a9d834dafdf10f0c70adda

envoy/api/v2/endpoint/endpoint.proto

@@ -37,7 +37,7 @@ message Endpoint {
     // as the host's serving address port. This provides an alternative health
     // check port. Setting this with a non-zero value allows an upstream host
     // to have different health check address port.
-    uint32 port_value = 1;
+    uint32 port_value = 1 [(validate.rules).uint32.lte = 65535];
   }
 
   // The optional health check configuration is used as configuration for the