[ML] Explain Log Rate Spikes: Brush styles not being applied on first render.

[walterra]

Kibana version: 8.4.0 BC

Describe the bug:

On initial render, the styles for the brushing component for the baseline and deviation time range don't get applied correctly. The brush handles don't have rounded corners and there's no gap between the brush handlers and badge labels:

Only a rerender, for example triggered by resize the browser window, applies the correct styles:

There are cases where running the analysis will trigger a resize because the analysis results table makes the page higher and dynamic scrollbars showing up trigger a resize. In this case the brushes would show up briefly as unstyled and then switch to the styles version:

Expected behavior:

The brushes should be styled correctly right from the start.

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[alvarezmelissa87]

Doing some testing to work out what's causing this bug and found that when there are no results and the spike analysis table isn't rendered the brush style is never applied: