infra: Add isolate server properties. These are necessary to work correctly with swarming. Bug: angleproject:5114 Change-Id: I634e408e523284a935b77f62b95c9bc85e9e997f Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2859982 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Yuly Novikov <ynovikov@chromium.org>