如何在Android中获取BLE扫描事件的精确时间戳？

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothManager;
import android.content.Context;
import android.os.SystemClock;

public class BLEScanner {
    private BluetoothAdapter mBluetoothAdapter;

    public BLEScanner(Context context) {
        // 初始化BluetoothAdapter
        BluetoothManager bluetoothManager = (BluetoothManager) context.getSystemService(Context.BLUETOOTH_SERVICE);
        mBluetoothAdapter = bluetoothManager.getAdapter();
    }

    public void startScan() {
        // 开始BLE扫描
        mBluetoothAdapter.startLeScan(mLeScanCallback);
    }

    public void stopScan() {
        // 停止BLE扫描
        mBluetoothAdapter.stopLeScan(mLeScanCallback);
    }

    private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
        @Override
        public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
            // 获取当前时间戳
            long timestamp = SystemClock.elapsedRealtime();

            // 处理扫描到的BLE设备信息
            // ...
        }
    };
}