Generate a temp certificate for OCP4 Trusted CA remediation

Lately, we've been experiencing issues with manual remediations timing
out during functional testing. This manifests in the following error:

   === RUN   TestE2e/Apply_manual_remediations
    <snip>
    helpers.go:1225: Running manual remediation '/tmp/content-3345141771/applications/openshift/networking/default_ingress_ca_replaced/tests/ocp4/e2e-remediation.sh'
    helpers.go:1225: Running manual remediation '/tmp/content-3345141771/applications/openshift/general/file_integrity_notification_enabled/tests/ocp4/e2e-remediation.sh'
    helpers.go:1231: Command '/tmp/content-3345141771/applications/openshift/authentication/idp_is_configured/tests/ocp4/e2e-remediation.sh' timed out

In this particular case, it looks like the remediation to add an
Identity Provider to the cluster failed, but this is actually an
unintended side-effect of another change that updated the
idp_is_configured remediation to use a more robust technique for
determining if the cluster applied the remediation successfully:

  #12120
  #12184

Because we updated the remediation to use `oc adm
wait-for-stable-cluster`, we're effectively checking all cluster
operators to ensure they're healthy.

This started causing timeouts because a separate, unrelated remediation
was also getting applied in our testing that updated the default CA, but
didn't include a ConfigMap that contained the CA bundle. As a result,
one of the operators didn't come up because it was looking for a
ConfigMap that didn't exist. The `oc adm wait-for-stable-cluster`
command was hanging on a legitimate issue in a separate remediation.

This commit attempts to fix that issue by updating the trusted CA
remediation by generating a certificate for testing purposes, then
creates a ConfigMap called `trusted-ca-bundle`, before updating the
trusted CA.

applications/openshift/networking/default_ingress_ca_replaced/tests/ocp4/e2e-remediation.sh

@@ -1,4 +1,10 @@
 #!/bin/bash
 
-# we are using an existing default secret name for testing, so it won't cause any subsequent failures on testing routes. 
+# Generate a new certificate. The details of the certificate don't really
+# matter since we simply need it for the ConfigMap so that the cluster
+# operators come back up after the trustedCA change.
+openssl req -x509 -newkey rsa:4096 -keyout /tmp/key.pem -out /tmp/cert.pem -sha256 -days 365 -nodes -subj "/C=XX/ST=StateName/L=CityName/O=CompanyName/OU=CompanySectionName/CN=CommonNameOrHostname"
+oc create configmap trusted-ca-bundle --from-file=ca-bundle.crt=/tmp/cert.pem -n openshift-config
+
+# we are using an existing default secret name for testing, so it won't cause any subsequent failures on testing routes.
 oc patch proxies.config cluster --type merge -p '{"spec":{"trustedCA":{"name":"trusted-ca-bundle"}}}'