Remove the disablement of arc.PIPRoundedCornersUnderlay

We don't need to override the disablement on Chrome side, since the
original tests is already disabled on betty (crrev.com/c/3805246) and
is skipped on Chrome side regardless of the existence of this
entry.

CQ_INCLUDE_TRYBOTS=luci.chrome.try:chromeos-betty-pi-arc-chrome
CQ_INCLUDE_TRYBOTS=luci.chrome.try:chromeos-eve-chrome
CQ_INCLUDE_TRYBOTS=luci.chrome.try:chromeos-kevin-chrome
CQ_INCLUDE_TRYBOTS=luci.chrome.try:chromeos-octopus-chrome
CQ_INCLUDE_TRYBOTS=luci.chrome.try:chromeos-reven-chrome
CQ_INCLUDE_TRYBOTS=luci.chrome.try:lacros-amd64-generic-chrome

Bug: 1350880
Test: CQ passes
Change-Id: I8c15300eb16d6c3e2cca4ecc293eb17fbae2c6a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3868634


Auto-Submit: Yoshiki Iguchi <yoshiki@chromium.org>
Commit-Queue: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Reviewed-by: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1045909}