Remove popup collection duplicate test

Remove unit test that was testing the same behavior as these two tests:
- PopupsClose_OnBubbleHeightChangedUsedAvailableSpace
- BaselineUpdates_OnTrayBubbleShownWithMultiDisplay

Combining these two behaviors does not produce a different outcome than
them being tested independently, so this test can be removed.

Bug: b:300004520
Change-Id: Iaf40def2a4f826490fda54e343337c3f3b7a5f75
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4859263
Commit-Queue: Kevin Radtke <kradtke@chromium.org>
Reviewed-by: Andre Le <leandre@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1195706}