要防止在Android设备上设置任何密码，可以使用设备管理器API。以下是一个示例代码，演示如何使用设备管理器API禁用密码设置：

1. 首先，在AndroidManifest.xml文件中添加设备管理器权限：

2. 创建一个继承自DeviceAdminReceiver的广播接收器类，用于处理设备管理器事件：

public class MyDeviceAdminReceiver extends DeviceAdminReceiver {
    // Leave this class empty
}

3. 在你的活动类中，注册设备管理器：

private static final int REQUEST_ENABLE_ADMIN = 1;

private void enableDeviceAdmin() {
    ComponentName componentName = new ComponentName(this, MyDeviceAdminReceiver.class);
    Intent intent = new Intent(DevicePolicyManager.ACTION_ADD_DEVICE_ADMIN);
    intent.putExtra(DevicePolicyManager.EXTRA_DEVICE_ADMIN, componentName);
    intent.putExtra(DevicePolicyManager.EXTRA_ADD_EXPLANATION, "Enable device admin");
    startActivityForResult(intent, REQUEST_ENABLE_ADMIN);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_ENABLE_ADMIN) {
        if (resultCode == RESULT_OK) {
            // Device admin enabled
            // Disable password setting
            disablePasswordSetting();
        } else {
            // Device admin not enabled
            // Handle accordingly
        }
    }
}

private void disablePasswordSetting() {
    DevicePolicyManager devicePolicyManager = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
    ComponentName componentName = new ComponentName(this, MyDeviceAdminReceiver.class);

    // Set password quality to none
    devicePolicyManager.setPasswordQuality(componentName, DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED);

    // Set password minimum length to 0
    devicePolicyManager.setPasswordMinimumLength(componentName, 0);

    // Set password expiration timeout to 0
    devicePolicyManager.setMaximumTimeToLock(componentName, 0);
}

4. 在你的活动类的onCreate()方法中调用enableDeviceAdmin()方法：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    enableDeviceAdmin();
}

通过执行上述步骤，设备管理器将被启用，并且将禁用密码设置。请注意，用户必须在设备上确认授予设备管理员权限。