CLOUDSTACK-8687: Unit tests for validating the prepare template functionality.

These tests validate that the templates get scheduled for seeding. Additionally,
if a template is already seeded, we do not try and seed it again. Tests also
validate that templates are seeded to storage pools which are available.

Author: devdeep

server/src/com/cloud/template/TemplateManagerImpl.java

@@ -269,10 +269,10 @@ public class TemplateManagerImpl extends ManagerBase implements TemplateManager,
     MessageBus _messageBus;
 
     private boolean _disableExtraction = false;
-    private ExecutorService _preloadExecutor;
-
     private List<TemplateAdapter> _adapters;
 
+    ExecutorService _preloadExecutor;
+
     @Inject
     private StorageCacheManager cacheMgr;
     @Inject