osbuild phase needs to wait for ostree phase in some cases, this patch
makes the various image build phases waiting for ostree phase, it may
introduce some slowdown, but it's still faster than the version before
PR#1790.
JIRA: RHELCMP-14349
Fixes: https://pagure.io/pungi/issue/1816
Signed-off-by: Haibo Lin <hlin@redhat.com>
(cherry picked from commit b3e0b6d7b73c48588b9aacd933f3e0e8ae3506ac)