Call with Nheko doesn't work

### Steps to reproduce

Description copied over from https://github.com/Nheko-Reborn/nheko/issues/1331

>Place a call between Nheko on PinePhone and Element Android. It says “Connecting” for a few seconds, then the call is automatically ended, and an in-app notification is displayed in Nheko at the top of the app that says “Call connection failed”.
I'm not sure if it's a bug in Nheko or Element Android.

> version:
- latest Element Android (previous versions are also affected), tested on multiple Android versions and phone models
- postmarketOS Phosh v22.12 on PinePhone (not tested other OS, but might be affected)
- latest Nheko from Flatpak (not tested other versions or installation methods, but might be affected)

> other details:
- PinePhone tested only on mobile data, Android tested on Wi-Fi, or mobile data
- call reliably works between Element iOS and Nheko (doesn't matter if the iPhone is on Wi-Fi or mobile data)

> Worth noting that Element Android is known for slow connection. Sometimes establishing the connection between two Element Android session takes 20-30 seconds, or entirely fails for the first time, and only succeeds after ending the call, and placing a new call, but it takes at least 10 seconds for the second call, most of the time. (Sometimes they don't connect at all, no matter how many times it is tried.)
**possible fix for Nheko**
The cause of the issue with calls between Nheko and Element Android could be that Element Android is slow, but Nheko ends the call with connection error too early. It is possible that increasing the connection timeout in Nheko to 30 seconds would solve the problem.

I'm not sure if the above described problem is the real cause. Even if it is, fixing the slow connection problem in Element Android is necessary for wider adoption.

### Your phone model

all models are affected

### Operating system version

all OS versions are affected

### Application version and app store

all installation methods are affected

### Homeserver

grin.hu

### Will you send logs?

No

### Are you willing to provide a PR?

No