CORD-536 updated to support the setting of repo via vars

Change-Id: If8b6a23fd48b2050f3dc64d55427da150268d5cb
diff --git a/ansible/roles/java8-oracle/tasks/main.yml b/ansible/roles/java8-oracle/tasks/main.yml
index 32fe37b..b46950a 100644
--- a/ansible/roles/java8-oracle/tasks/main.yml
+++ b/ansible/roles/java8-oracle/tasks/main.yml
@@ -5,7 +5,9 @@
 
 - name: Add Oracle Java repository
   become: yes
-  apt_repository: repo='ppa:webupd8team/java'
+  apt_repository:
+    repo: "{{ java_apt_repo | default('ppa:webupd8team/java') }}"
+    update_cache: yes
 
 - name: Accept Java 8 license
   become: yes