Switching apps during call resets audio device

### Steps to reproduce

1. Be in a 1:1 native call
2. switch apps to view a photo or website etc
3. switch back

### Outcome

#### What did you expect?
switching apps does not impact the audio device in use
#### What happened instead?
audio device is switched back to default, which in this case is the ear speaker instead of the loudspeaker (see #5368)

### Your phone model

7

### Operating system version

_No response_

### Application version

_No response_

### Homeserver

_No response_

### Will you send logs?

No

No files, tests, or entry points are named. Start by reproducing the issue during a 1:1 native call on the reported phone model, then trace the call audio handling across an app switch. Done means switching away and back preserves the loudspeaker or other audio device selected before the switch.

Written by the indexing model from the issue text.