Stickerpicker Widget Can't Download/Thumbnail Media

### Steps to reproduce

Open a stickerpicker widget that attempts to display media from the homeserver.

### Outcome

#### What did you expect?
Image should display correctly

#### What happened instead?
Image is broken, rejected with `401` and the response:
```json
{"errcode":"M_MISSING_TOKEN","error":"Missing access token"}
```

#### Additional context
Comparing the requests that Element Desktop makes to Element Android, Desktop includes the `Authorization: Bearer xxxxxxx` header in there automatically, perhaps by intercepting the fetch requests.

### Your phone model

Motorola Edge Plus 2023

### Operating system version

14

### Application version and app store

1.6.20 f-droid, 1.6.22-dev f-droid

### Homeserver

Synapse 1.114.0

### Will you send logs?

Yes

### Are you willing to provide a PR?

No