Can't upgrade audio call to video call

### Steps to reproduce

- Make audio call

/or/

- Make video call
- Disable camera

### Outcome

#### What did you expect?

Button is present that allows me, to enable my Camera

#### What happened instead?

On every platform, when an audio call is made, the Enable Camera button is not available.

On desktop the button was visible for a short second after disabling camera, and then disappeared
On web the button disappeared the moment i disabled video

### Operating system

Android/Chimera Linux/Web

### Application version

Web: Element version: 1.11.25 Olm version: 3.2.12 / Desktop: Element version: 1.11.24 Olm version: 3.2.12

### How did you install the app?

Flatpak/Web

### Homeserver

Synapse v1.78.0

### Will you send logs?

Yes