问如何将Firebase规则添加到特定用户的读写和所有其他用户仅读？

EN

service cloud.firestore {
  match /databases/{database}/documents {
    // Make sure the uid of the requesting user matches name of the user
    // document. The wildcard expression {userId} makes the userId variable
    // available in rules.
    match /users/{userId} {
      allow read, update, delete: if request.auth != null && request.auth.uid == userId;
      allow create: if request.auth != null;
    }
  }
}

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    // Line below secure whole database so users are not alowed to create any new collections etc.
    match /{document=**} {
      allow read, write: if false;
    }
    match /app/{dataId} {
      allow read: if true;
      allow write: if isAdmin();
    }
    match /posts/{dataId} {
        allow read: if resource.data.isPublic == true || isAdmin();
        allow write: if isAdmin();
    }
  }
}

function isAdmin() {
    return request.auth.token.admin == true;
}