JVM as variable, name all tasks, update README

roles/keycloak/tasks/prereqs.yml

@@ -1,5 +1,5 @@
 ---
-- name: "Validate configuration"
+- name: Validate configuration
   assert:
     that:
       - (keycloak_ha_enabled and keycloak_db_enabled) or (not keycloak_ha_enabled and keycloak_db_enabled) or (not keycloak_ha_enabled and not keycloak_db_enabled)
@@ -7,7 +7,7 @@
     fail_msg: "Cannot install HA setup without a backend database service. Check keycloak_ha_enabled and keycloak_db_enabled"
     success_msg: "{{ 'Configuring HA' if keycloak_ha_enabled else 'Configuring standalone' }}"
 
-- name: "Validate credentials"
+- name: Validate credentials
   assert:
     that:
       - (rhn_username is defined and rhsso_rhn_id is defined) or rhsso_rhn_id is not defined
@@ -16,14 +16,15 @@
     fail_msg: "Cannot install Red Hat SSO without RHN credentials. Check rhn_username and rhn_password are defined"
     success_msg: "{{ 'Installing Red Hat Single Sign-On' if rhsso_rhn_id is defined else 'Installing keycloak.org' }}"
 
-- set_fact:
+- name: Set required packages facts
+  set_fact:
     required_packages:
-    - "{{ jvm_package | default('java-1.8.0-openjdk-devel') }}"
+    - "{{ jvm_package }}"
     - unzip
     - procps-ng
     - initscripts
 
-- name: "Ensures required packages are installed"
+- name: Ensures required packages are installed
   ansible.builtin.include_tasks: fastpackages/install.yml
   vars:
     packages_list: "{{ required_packages }}"