FileInputStream must be closed, or there will be a risk of memory leaks.

Change-Id: I9186679875db3a01964dcafb8b4b64e9dd03655c
diff --git a/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosAppMojo.java b/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosAppMojo.java
index d97c89a..3bff799 100644
--- a/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosAppMojo.java
+++ b/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosAppMojo.java
@@ -269,6 +269,7 @@
                     .map(cfg -> expand(cfg.getRootNode().getValue().toString()))
                     .collect(Collectors.toList());
 
+            stream.close();
         } catch (ConfigurationException e) {
             throw new MojoExecutionException("Unable to parse app.xml file", e);
         } catch (FileNotFoundException e) {