Revert "[animation-worklet] Rename layout tests"

This reverts commit 46b03fcf88a29480afce6f0209cd17d872afa8e1.

Reason for revert:

Seems to break fast/events/middleClickAutoscroll-nested-divs.html on several platforms. Example here:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.10%20Tests/34202


Original change's description:
> [animation-worklet] Rename layout tests
> 
> Remove "animation-worklet-' prefix from layout tests. The tests are inside AW
> directory so the prefix is just visual clutter. I kept it for tests that check
> something about the worklet itself.
> 
> Note: There was a legacy unused animationworklet/visual-update-expected.html
> file that this patch replaces now.
> 
> Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
> Change-Id: I67a36d7d5913b1394108b8a1731cc660d74f99ad
> Reviewed-on: https://chromium-review.googlesource.com/1165271
> Reviewed-by: Majid Valipour <majidvp@chromium.org>
> Reviewed-by: Yi Gu <yigu@chromium.org>
> Commit-Queue: Majid Valipour <majidvp@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#581552}

TBR=majidvp@chromium.org,yigu@chromium.org

Change-Id: If81712c7089784772b5a106159c70bdd7cbce9c8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Reviewed-on: https://chromium-review.googlesource.com/1167766
Reviewed-by: Fredrik Hubinette <hubbe@chromium.org>
Commit-Queue: Fredrik Hubinette <hubbe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581653}