code: public void getMemberInfo(final String memberId, final AVIMConversationMemberQueryCallback callback) {
      QueryConditions conditions = new QueryConditions();
      conditions.addWhereItem("cid", QueryOperation.EQUAL_OP, this.conversationId);
      conditions.addWhereItem("peerId", QueryOperation.EQUAL_OP, memberId);
      queryMemberInfo(conditions, callback);
    }
docs: 获取对话内指定成员的角色信息
  @param memberId  成员的 clientid
  @param callback  结果回调函数