[Doc 7.3.0.Beta] referencing eap72

I have found 4 occurences of `eap72` in [1]

1. chapter 4.2. Import JDK 11 Image
2. chapter 4.3. Deploy a JBoss EAP S2I Application to OpenShift using JDK 11 Image
3. chapter 7.9.1. Configuring External Red Hat AMQ Brokers
4. chapter 1.5. Technology Preview Features

[1] https://doc-stage.usersys.redhat.com/documentation/en-us/red_hat_jboss_enterprise_application_platform/7.3.beta/html-single/getting_started_with_jboss_eap_for_openshift_container_platform/#version_compatibility_support