LibvirtComputingResource: Expose KVMStoragePoolManager

KVMStoragePoolManager is a singleton in practice, any plugin
or extension of LibvirtComputingResource will need to act on
the specific instance of KVMStoragePoolManager that LibvirtComputingResource
has initialized. Therefore, expose this variable for those who
wish to call storage commands from plugins or extensions.

plugins/hypervisors/kvm/src/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java

@@ -3922,6 +3922,10 @@ ServerResource {
         return _storagePoolMgr.disconnectPhysicalDiskByPath(path);
     }
 
+    protected KVMStoragePoolManager getPoolManager() {
+        return _storagePoolMgr;
+    }
+
     protected synchronized String attachOrDetachISO(Connect conn,
             String vmName, String isoPath, boolean isAttach)
                     throws LibvirtException, URISyntaxException, InternalErrorException {