Move gate-manila-buildimage-docker job to check pipeline
Move gate-manila-buildimage-docker job to check pipeline

Tox job for building docker image is merged to manila-image-elements [1]
project. Add it to check pipeline to run it with each change.

[1] I499fa1850d3ad197cab5f742bfca1a9f074e9a8b

Change-Id: Ia575cb9cc4bad4a559761d681deb6f7cabb9e1f6

dongwenjuan/project-config,openstack-infra/project-config,Tesora/tesora-project-config,openstack-infra/project-config,dongwenjuan/project-config,Tesora/tesora-project-config