[Leasing server] Support NO_RESOURCE swarming state
[Leasing server] Support NO_RESOURCE swarming state

Bug: skia:9523
Change-Id: I72cb227b3ef2b0797e55439c4ab545be9cffd733
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/247676
Reviewed-by: Kevin Lubick <7cdab2cfab351f23814786ba39716e90eed69047@google.com>
Commit-Queue: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot