发送好友申请

OpenIMClient.getInstance().friendshipManager.addFriend(
    new OnBase<String>() {
        @Override
        public void onSuccess(String data) {
            markFriendApplicationSubmitted();
        }

        @Override
        public void onError(int code, String error) {
            recordFriendApplicationFailure(code, error);
        }
    },
    "user_b",
    "你好，我是 Alex"
);