Merge cloudbots codes from TOT to all release branches
BUG=b:336556314

[cloudbots][cft] Add IsAlive check when reboot through cloudbots

BUG=b:325553505
TEST=cros_sdk cros-workon --host start cros-dut, cros_sdk sudo emerge cros-dut, bniche-test cros-tool-runner on cloudbot VM

Change-Id: Id4b738e61d104295c7bd162c28f066caa1ce557e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5388456
Tested-by: Bryan Ni <bniche@google.com>
Reviewed-by: Azizur Rahman <azrahman@google.com>
Reviewed-by: Sergey Fetisov <sfetisov@google.com>
Reviewed-by: Derek Beckett <dbeckett@chromium.org>
Commit-Queue: Bryan Ni <bniche@google.com>
(cherry picked from commit a7464ae6717a6d4a9ad7161c5e981494656842b9)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5513107