DDoS Attacks and Repair Solutions for this bug of netcloud

### ⚠️ Before posting ⚠️

- [x] This is a **bug**, not a question or an enhancement.
- [x] I've [searched for similar issues](https://github.com/nextcloud/android/issues) and didn't find a duplicate.
- [x] I've written a clear and descriptive title for this issue, not just "Bug" or "Crash".
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/).

### Steps to reproduce

Hello, author. I've discovered a service in the project:

This service is set to be exported and has no permission settings.
I launched a DDoS attack on it, which caused the app to experience denial of service and crash (the attack implementation is recorded in （https://meeting.tencent.com/crm/KEVnYVRe89),and the attack apk is in (通过网盘分享的文件：attacknetcloud.apk
链接: https://pan.baidu.com/s/19l0ROuVJC3CSt1VixKi9WA?pwd=8y9w 提取码: 8y9w)

Based on this, I've come up with corresponding solutions and code. You can repair this bug by update the
AndroidManifest.xml file:

### Expected behaviour

I launched a DDoS attack on it, which caused the app to experience denial of service and crash (the attack implementation is recorded in （https://meeting.tencent.com/crm/KEVnYVRe89),

### Actual behaviour

I launched a DDoS attack on it, which caused the app to experience denial of service and crash（https://meeting.tencent.com/crm/KEVnYVRe89),

### Android version

>=12.0

### Device brand and model

android 15.0 x86

### Stock or custom OS?

Stock

### Nextcloud android app version

3.31.1

### Nextcloud server version

31.0.3.2

### Using a reverse proxy?

I don't know

### Android logs

_No response_

### Server error logs

```bash

```

### Additional information

_No response_