PIP video sending fails if lockscreen PIN / FaceID configured

### Steps to reproduce

1. Set up a lockscreen PIN in the app (with FaceID, which may or may not matter)
2. Restart the app
3. Open a video call
4. Background the app
5. Discover that you are no longer sending video.
6. Without PIN, it works however.

### Outcome

#### What did you expect?

Video sending should work when PIPed even if you have lockscreen set up. Presumably we shouldn't lock the app if you bg when on a video call (but also shouldn't introduce other security holes)

### Your phone model

_No response_

### Operating system version

_No response_

### Application version

704

### Homeserver

_No response_

### Will you send logs?

No