ci-operator/step-registry/openshift/e2e/test: Add TEST_COMMAND and TEST_SUITE

Taking advantage of openhsift/ci-tools@62e7498d66 (ci-operator
multi-stage: add step parameters, 2020-05-27, openshift/ci-tools#854).
This commit doesn't override the defaults yet, but a useful override
would be:

  TEST_COMMAND=run-upgrade
  TEST_SUITE=all

This replaces test-suite.txt, which landed in a2fd8c3
(step-registry: add Origin E2E test step, 2020-01-31, openshift#6965), and also
had no consumers.

Author: wking

ci-operator/step-registry/openshift/e2e/test/openshift-e2e-test-commands.sh

@@ -62,12 +62,7 @@ if [[ "${CLUSTER_TYPE}" == gcp ]]; then
     popd
 fi
 
-test_suite=openshift/conformance/parallel
-if [[ -e "${SHARED_DIR}/test-suite.txt" ]]; then
-    test_suite=$(<"${SHARED_DIR}/test-suite.txt")
-fi
-
-openshift-tests run "${test_suite}" \
+openshift-tests "${TEST_COMMAND}" "${TEST_SUITE}" \
     --provider "${TEST_PROVIDER}" \
     -o /tmp/artifacts/e2e.log \
     --junit-dir /tmp/artifacts/junit

ci-operator/step-registry/openshift/e2e/test/openshift-e2e-test-ref.yaml

@@ -2,6 +2,13 @@ ref:
   as: openshift-e2e-test
   from: tests
   commands: openshift-e2e-test-commands.sh
+  env:
+  - name: TEST_COMMAND
+    default: run
+    documentation: The test command to run.  Use 'openshift-test --help' to list available commands.
+  - name: TEST_SUITE
+    default: openshift/conformance/parallel
+    documentation: The test suite to run.  Use 'openshift-test TEST_COMMAND --help' to list available suites.
   resources:
     requests:
       cpu: "3"