要在Android中发送POST请求到Google Sheet脚本，可以使用HttpURLConnection类来建立连接并发送请求。以下是一个示例代码：

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class GoogleSheetPOST {
    private static final String SCRIPT_URL = "https://script.google.com/macros/s/your_script_id/exec";

    public static void sendPOSTRequest() throws IOException {
        URL url = new URL(SCRIPT_URL);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        // 设置请求方法为POST
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type", "application/json");

        // 设置请求参数
        String jsonInputString = "{\"data\": \"Hello from Android!\"}";

        // 启用输出流，向服务器发送数据
        connection.setDoOutput(true);
        DataOutputStream outputStream = new DataOutputStream(connection.getOutputStream());
        outputStream.writeBytes(jsonInputString);
        outputStream.flush();
        outputStream.close();

        // 获取响应状态码
        int responseCode = connection.getResponseCode();

        // 读取响应内容
        BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        String inputLine;
        StringBuilder response = new StringBuilder();
        while ((inputLine = reader.readLine()) != null) {
            response.append(inputLine);
        }
        reader.close();

        // 打印响应结果
        System.out.println("Response Code: " + responseCode);
        System.out.println("Response: " + response.toString());
    }

    public static void main(String[] args) {
        try {
            sendPOSTRequest();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

请注意，你需要将SCRIPT_URL替换为你的Google Sheet脚本的URL。jsonInputString是你要发送的JSON数据。

这是一个简单的示例，你可以根据你的需求进行修改和扩展。