Re-enable legacy plugin warning icon before legacy paths are disabled #14029

Tracking issue only. Do not open PRs against this task.

Based on user feedback during beta, the warning icon makes the plugin manager dialog more alarming than it needs to be at this current point in time.

We'll be temporarily removing the icon for 33.0 and this is a tracking issue to ensure we enable it again later.

Currently I'd expect that to be version 33.2.