operator manifests: Unify configuration naming
operator manifests: Unify configuration naming

Change operator_manifest in container.yaml to operator_manifestS to
unify it with the reactor-config-map option.

Signed-off-by: Adam Cmiel <1217f9865bd733d1bcad0d0d64be310272c5592c@redhat.com>

projectatomic/osbs-client,projectatomic/osbs-client