[Reader IA] The animation expanding the Top UI is a bit laggy

[daniloercoli]

While testing #19882 I noticed that transitioning from Discovery to Subscriptions on my device is slow, and briefly, I can see the first pill labeled "Subscriptio" until the UI fully expands.
Below is a recording of the problem.

screen-20240112-212150.mp4

[thomashorta]

Can you test a more recent build from the feature/reader-ia branch (ideally compiling locally or maybe one published in the comments of this issue: #19911)?

It looks like you used an old build of the feature/reader-ia branch and I did some work on a few animations and request-related code to try to make the animations smoother after that. Just to make sure we're not looking at an issue that was already solved. Thanks!