No avatars or displaynames when scrolling up (Conduit)

#### Describe the bug
Conduit bug:

When scrolling up a bit in a room, avatars and displaynames don't show anymore even though they worked for the same users in the most recent part of the timeline. I assume this is because Conduit does not support lazy loading, but should Element Android rely on lazy loading so much?

#### To Reproduce
1. Log in to an account on the conduit.rs homeserver
2. Join #general:conduit.rs
3. Scroll up

#### Additional context
- App version and store 1.1.8 Play Store