cluster-launch-installer-e2e: Start setting expirationDate again

We'd dropped this in 3f2f01c
(ci-operator/config/openshift/installer/master: Move to
openshift-install, 2018-09-26, #1677).  But since
openshift/installer@98a35316 (pkg/asset/installconfig: Add
_CI_ONLY_STAY_AWAY_OPENSHIFT_INSTALL_AWS_USER_TAGS, 2018-09-28,
openshift/installer#364), the installer supports setting it again, so
we can add it back.

As the name suggests, this variable is not a stable API.  Soon the new
installer will be able to load the configuration from YAML (again),
but we can keep adjusting as the installer evolves.

ci-operator/templates/openshift/installer/cluster-launch-installer-e2e.yaml

@@ -232,10 +232,12 @@ objects:
  - name: OPENSHIFT_INSTALL_RELEASE_IMAGE_OVERRIDE
  value: ${RELEASE_IMAGE_LATEST}
  command:
- - /bin/openshift-install
- - --dir=/tmp/artifacts/installer
- - --log-level=debug
- - cluster
+ - /bin/sh
+ - -c
+ - |
+ #!/bin/sh
+ export _CI_ONLY_STAY_AWAY_OPENSHIFT_INSTALL_AWS_USER_TAGS="{\"expirationDate\": \"$(date -d '4 hours' --iso=minutes --utc)\"}"
+ exec /bin/openshift-install --dir=/tmp/artifacts/installer --log-level=debug cluster
 
  # Performs cleanup of all created resources
  - name: teardown