Add fix for Download-Only deployment type on DDI-API (#848)

Signed-off-by: Jeroen Laverman <jeroen.laverman@bosch-si.com>

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/Action.java

@@ -142,6 +142,13 @@ public interface Action extends TenantAwareBaseEntity {
         return ActionType.FORCED == getActionType();
     }
 
+    /**
+     * @return true when action is downloadonly, false otherwise
+     */
+    default boolean isDownloadOnly() {
+        return ActionType.DOWNLOAD_ONLY == getActionType();
+    }
+
     /**
      * Action status as reported by the controller.
      *