Failed to compile when using google protobuf files

[HeyJavaBean]

Describe the bug
cloudwego/kitex#835
When importing google protobuf files, such as timestamp, those structs don't have fastpb interface, so users cannot compile codes.

To Reproduce

syntax = "proto3";
 
option go_package = "pbdemo";
import "google/protobuf/timestamp.proto";

package pbdemo;
 
service ServiceA {
  rpc SayHello (Request) returns (Reply) {}
}
 
message Request {
  string name = 1;
  google.protobuf.Timestamp date = 4;
}
 
message Reply {
  string message = 1;
}