Revert "[SPv175] Borrow the SPv2 bot for SPv175"

This reverts commit b104c05adb6aed5da5dae9f51ddaca93c886f823.

Reason for revert: Now SPv175 is live on M66, so return the bot
to SPv2.

Also update LayoutTests/FlagExpectations/enable-slimming-paint-v2.

Original change's description:
> [SPv175] Borrow the SPv2 bot for SPv175
>
> We are near to finish SPv175 development, and we need more test
> coverage. Borrow the SPv2 bot for SPv175 until we switch SPv175
> on for experiment.
>
> Bug: 771643
> Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
> Change-Id: I05f36f168269507961cdc102446e4b23159555dd
> TBR: testing/buildbot
> Reviewed-on: https://chromium-review.googlesource.com/860726
> Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#528517}

TBR=wangxianzhu@chromium.org,trchen@chromium.org,chrishtr@chromium.org,schenney@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 771643
Change-Id: Ib0e31c9e542936a0ac3baddf17b4896eff7aed47
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Reviewed-on: https://chromium-review.googlesource.com/925021
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537590}
249 files changed