Wrong placement of encryption-enabled and start-of-history UI elements

#### Describe the bug

The "Encryption enabled" and "This is the beginning of ROOM_NAME history" signs can end up in the wrong place sometimes, *after* some messages and not at the actual start of history. This may be an unforeseen interaction with the recent implementation of https://github.com/uhoreg/matrix-doc/blob/shareable_keys_msc/proposals/3061-shareable-room-keys.md in Element Web.

#### To Reproduce
Steps to reproduce the behavior:
1. Create a room from Element Web.
2. Send some messages.
3. Invite an account using Element Android.
4. Join the room.
5. The "Encryption enabled" and "This is the beginning of ROOM_NAME history." signs are in the wrong place, below the messages sent in step 2.

#### Expected behavior
The signs should be at the actual start of history, at the point where room creation/setup events were sent.

#### Screenshots

#### Smartphone (please complete the following information):
- Device: Xiaomi Mi A3
- OS: Android 10

#### Additional context
- App version: Element Android 1.1.7