Move LAVA tests to the end of pipeline

Start of tests must be the last step in pipeline to avoid omissions
of images build caused by wrong tests description.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>
Reviewed-by: Luis Araujo <luis.araujo@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D7735