[Leasing server] Use device type for iOS leases
[Leasing server] Use device type for iOS leases

Bug: skia:10127
Change-Id: I2b6fd9091d7ec24b121b4f1b9110f90696f6162f
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/282580
Reviewed-by: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@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