Fix bug of HC historical results not showing top 20/30

[ohltyler]

Signed-off-by: Tyler Ohlsen ohltyler@amazon.com

Description

Fixes the bug of the filters for "Top 20" / "Top 30" not updating correctly when selected for historical high-cardinality charts. The fix is to update the hook to use any existing filter state, rather than defaulting to "Top 10" and overriding any existing state.

Note that if the hook was working as expected, this original bug wouldn't exist, since it would only be triggered when changes to the props.detectorTaskProgress happen (when the historical task is running). But, it is actually being triggered when any filter selection is made. It was then found that the entire AnomalyHeatmapChart component is getting re-mounted whenever these filter changes are occurring, hence triggering this hook every time a re-mount happens.

Expected behavior:
User selects "Top 20" -> props.onDisplayOptionChanged is called -> AnomalyHeatmapChart component re-renders with updated set of anomalies and entity data -> renders top 20 entity results

What's happening currently:
User selects "Top 20" -> props.onDisplayOptionChanged is called -> AnomalyHeatmapChart is re-mounted (so all hooks will be triggered) -> the hook on props.detectorTaskProgress is triggered -> resetting the selected option to "Top 10" -> only showing top 10 entity results

I created #90 to track this, and will handle separately.

Issues Resolved

[List any issues this PR will resolve]

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