Fix scroll bar regression

Summary:
Changelog: [Logs] Fix regression causing the scrollbars to be hidden. This diff fixes a regression where the Logs plugin was no longer scrollable (and scrolls indefinitely, killing perf).

As reported in https://fb.workplace.com/groups/flippersupport/permalink/1133775743769749/

The cause of the problem is the swap between the `PluginContainer` and `outOfContentsContainer`.

The deeper root that caused in the first place, is that containers use a `flex: 1` layout, which gets interpreted as `flex: 1 1 0%` (grow, shrink, 0% by default), where it was always inteded to be `flex: 1 1 0` (grow, shrink, by default zero pixels). In practice that difference usually doesn't matter. But sometimes it does... See https://stackoverflow.com/a/42630660/1983583

My whole life has been a lie up to this point.

Will trigger a new release after landing this.

Reviewed By: nikoant

Differential Revision: D28422966

fbshipit-source-id: 3ebd5f8ae76e032c5d698154b021df8ebef2c757

desktop/flipper-plugin/src/data-source/DataSourceRendererVirtual.tsx

@@ -325,7 +325,8 @@ const tableContainerStyle = {
   overflowY: 'auto',
   overflowX: 'hidden',
   display: 'flex',
-  flex: 1,
+  // because: https://stackoverflow.com/questions/37386244/what-does-flex-1-mean
+  flex: `1 1 0`,
 } as const;
 
 const tableWindowStyle = {