This adds new conditonal arguments --device-type and --device-os
(shortened as -t and -o) that specify an Android device type/OS.
In practice only -t is usually necessary. Also makes the GPU
dimension optional (-g or --gpu).

Bug: angleproject:5109
Bug: chromium:1133459
Change-Id: Id975c676db40e9eb104b73a4ed5858e6083cbd70
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2439481Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>