policy: direct response -- add response headers

policy/v1beta1/cfg.proto

@@ -167,11 +167,11 @@ message Rule {
   }
 
   // Optional. Templatized operations on the request headers using values produced by the
-  // rule actions.
+  // rule actions. Require the check action result to be OK.
   repeated HeaderOperationTemplate request_header_operations = 3;
 
   // Optional. Templatized operations on the response headers using values produced by the
-  // rule actions.
+  // rule actions. Require the check action result to be OK.
   repeated HeaderOperationTemplate response_header_operations = 4;
 
   // $hide_from_docs

policy/v1beta1/http_response.proto

@@ -26,6 +26,9 @@ message DirectHttpResponse {
 
   // HTTP response body.
   string body = 2;
+
+  // Optional HTTP response headers.
+  map<string, string> headers = 3;
 }
 
 // HTTP response codes.

proto.lock

@@ -4914,6 +4914,16 @@
                 "name": "body",
                 "type": "string"
               }
+            ],
+            "maps": [
+              {
+                "key_type": "string",
+                "field": {
+                  "id": 3,
+                  "name": "headers",
+                  "type": "string"
+                }
+              }
             ]
           }
         ]