Call at the same time don't work

### Steps to reproduce

Start a call from Element Android, and the callee starts a call in the same time from another Element Android to the caller. So 2 Element Android calling each other at the same time.

### Outcome

#### What did you expect?
We can talk.

#### What happened instead?
Both phones display the outgoing call screen, and no can answer. If one caller ends their outgoing call, the incoming call doesn't ring and can't answer. Only if the incoming call arrives when there is no outgoing call screen.

When one use Element Desktop or Web, and one use Element Android, it works, and we can talk. But not between 2 phones.

### Your phone model

happens with every phone

### Operating system version

newer Android (all tested was newer than 8)

### Application version and app store

1.4.2

### Homeserver

_No response_

### Will you send logs?

No