Joining video calls / conference rooms causes call to be sent to everyone else in the room

### Steps to reproduce

1. Create a Video Room / Conference in Element Desktop
2. Have multiple people join the room, they don't have to join the call itself.
3. Enter the room and press the call button on top right, it will put you in the conference room. But any user not in the current video call will get an incoming call.


### Outcome

#### What did you expect?
When I join a video call on a room that is a "conference/video room" I expect to be able to do that quietly. Optimally it would autojoin the video call green room when entering the room, just like on desktop. The room is a common meeting point where people drop in and out when they have a break and chat for a bit.

#### What happened instead?
A call, with notification and ringtone, went out to all the people that had joined the room, which caused issue due to a lot of the people in the room lives in different timezones, waking people up.

### Your phone model

Oneplus 8 Pro

### Operating system version

13

### Application version and app store

0.7.5 Google Store

### Homeserver

Synapse v1.120.0

### Will you send logs?

No

### Are you willing to provide a PR?

No