feat(api): Add RDP target attributes

internal/proto/controller/api/resources/targets/v1/target.proto

@@ -223,6 +223,11 @@ message Target {
       (custom_options.v1.generate_sdk_option) = true,
       (custom_options.v1.subtype) = "ssh"
     ];
+    RdpTargetAttributes rdp_target_attributes = 203 [
+      (google.api.field_visibility).restriction = "INTERNAL",
+      (custom_options.v1.generate_sdk_option) = true,
+      (custom_options.v1.subtype) = "rdp"
+    ];
   }
 
   // Output only. The available actions on this resource for this user.
@@ -323,6 +328,30 @@ message SshTargetAttributes {
   ]; // @gotags: `class:"public" eventstream:"observation"`
 }
 
+// RdpTargetAttributes contains attributes relevant to Targets of type "rdp"
+message RdpTargetAttributes {
+  // The default RDP port that will be used when connecting to the endpoint unless overridden by a Host Set or Host.
+  // If this is not specified the DefaultPort will be 3389.
+  google.protobuf.UInt32Value default_port = 10 [
+    json_name = "default_port",
+    (custom_options.v1.generate_sdk_option) = true,
+    (custom_options.v1.mask_mapping) = {
+      this: "attributes.default_port"
+      that: "DefaultPort"
+    }
+  ]; // @gotags: `class:"public"`
+
+  // The default RDP port that will be listened on by the client's local proxy.
+  google.protobuf.UInt32Value default_client_port = 20 [
+    json_name = "default_client_port",
+    (custom_options.v1.generate_sdk_option) = true,
+    (custom_options.v1.mask_mapping) = {
+      this: "attributes.default_client_port"
+      that: "DefaultClientPort"
+    }
+  ]; // @gotags: `class:"public"`
+}
+
 // WorkerInfo contains information about workers, returned in to the client in SessionAuthorization
 message WorkerInfo {
   // Output only. The address of the worker.