Room transition animation happens twice since #2059

[frebib]

Steps to reproduce

1. Open a room from the room list
2. Observe that the app now transitions once to the "unloaded room" and again to the "loaded room"

It's mostly visible on slower devices (my phone is new so is pretty quick, but enabling battery saver emulates it a little)

Outcome

What did you expect?

The previous behaviour. Reverting #2059 goes back to the old/expected behaviour.
Specifically, it seems that the issue is that there is a transition from the "unloaded timeline" to the "loaded timeline" whereas before it didn't do that.

What happened instead?

Here's a video I tried to capture of it happening. It's most visible in the last room opened

slow.mo.mp4

Your phone model

No response

Operating system version

No response

Application version and app store

No response

Homeserver

No response

Will you send logs?

Yes

Are you willing to provide a PR?

No

[jmartinesp]

I uploaded the video here in slow motion so it's a bit easier to see the issue. For whoever fixes this: take a look at the top app bar.