Add a new test job to use the configurable vKMS driver to test hotplugs
from `aosp/platform_testing/tests/display/hcct/tests/hotplugs.cpp`
Skip the test `DetectSingleDisconnectHotplugs` which currently fails
because it expects drm-hwcomposer to send a disconnect event for the
primary display. When this test is updated on a public branch of
platform_testing, it will be added back to the CI job.
Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>