Skip earlier to run 2x faster

This CL adds a new test rule to allow a test case to run only on either
extended (or projected) mode devices.
Currently, the assumption check is done at the beginning of each test
case, but as the setup stage of some test rules takes time it’s better
to skip the test before these setups begin.

The averaged run time is improved from 6m10s to 3m5s.

Flag: EXEMPT - test improvement
Bug: 419150275
Bug: 419122560
Test: atest WMShellSmokeTestsDesktopMode

Change-Id: Ie3c06eb8597ac630d6efd6055725da5f77b2d481