Set JAVA_HOME to the default java installation

Some roles depend on JAVA_HOME set in java_env.sh.

JIRA INFRA-1405

molecule/default/tests/test_default.py

@@ -24,11 +24,12 @@ def test_java_version(host):
 
 def test_java_home(host):
     cmd = host.run(r'su -l -c "echo \$JAVA_HOME"')
-    assert cmd.stdout.strip() == JAVA_HOME
-    assert host.file(JAVA_HOME).exists
+    java_home = cmd.stdout.strip()
+    assert host.file(java_home).exists
     if host.ansible.get_variables()["inventory_hostname"] == "ics-ans-role-java-and-oracle-jdk8":
-        cmd = host.run(r'su -l -c "echo \$JAVA8_HOME"')
-        assert cmd.stdout.strip() == JAVA8_HOME
+        assert java_home == JAVA8_HOME
+    else:
+        assert java_home == JAVA_HOME
 
 
 def test_javafx_home(host):

templates/java_env.sh.j2

-export JAVA_HOME="{{ java_openjdk_home }}"
-export PATH_TO_FX="{{ java_openjfx_home }}/lib"
 {% if java_install_oracle_jdk8 %}
-export JAVA8_HOME="{{ java_oracle_jdk8_home }}"
+export JAVA_HOME="{{ java_oracle_jdk8_home }}"
+{% else %}
+export JAVA_HOME="{{ java_openjdk_home }}"
 {% endif %}
+export PATH_TO_FX="{{ java_openjfx_home }}/lib"