Revert "Add manatee halt/poweroff/reboot logic."

This reverts commit 7a9bc4fbe5897a8b7f52218f4236bb3af604445b because we
now have a way for crosvm to signal the caller (hypervisor in this case)
whether the guest has requested restart or shutdown).

BUG=b:197259207
TEST="reboot", "poweroff" on brya-manatee.

Change-Id: Ibe85880fbd6fd13d36a50822ab38c4d33d5f33c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/upstart/+/3322110
Reviewed-by: Junichi Uekawa <uekawa@chromium.org>
Reviewed-by: Allen Webb <allenwebb@google.com>
Tested-by: Dmitry Torokhov <dtor@chromium.org>
Commit-Queue: Dmitry Torokhov <dtor@chromium.org>
2 files changed