Avatar missing on live location share

### Steps to reproduce

1. Be in a room with someone who starts LLS
2. Open the map
3. Observe that their avatar is not shown on their map - just their initial.

### Outcome

#### What did you expect?

Avatar to be shown properly.

#### What happened instead?

No avatar.

### Your phone model

iPhone 12 Pro Max

### Operating system version

iOS 15.4

### Application version

1.8.22

### Homeserver

matrix.org

### Will you send logs?

No

Reproduce live location sharing on an iPhone 12 Pro Max running iOS 15.4, using the listed steps, and inspect the iOS map and avatar display flow. Done means the other person's avatar appears on the live location map instead of only their initial.

Written by the indexing model from the issue text.