Use try-with-resources instead of the old-style finally block

Change-Id: If0d7bd488b83c545915d50a1bf253f4d6c2eaca9
diff --git a/src/main/java/com/googlesource/gerrit/plugins/serverconfig/ServerConfigServlet.java b/src/main/java/com/googlesource/gerrit/plugins/serverconfig/ServerConfigServlet.java
index 4d6324b..fd254cf 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/serverconfig/ServerConfigServlet.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/serverconfig/ServerConfigServlet.java
@@ -146,12 +146,9 @@
     res.setContentType("application/octet-stream");
     res.setContentLength(message.length());
     byte[] bytes = message.getBytes(Charsets.UTF_8);
-    ByteArrayInputStream in = new ByteArrayInputStream(bytes);
     OutputStream out = res.getOutputStream();
-    try {
+    try (ByteArrayInputStream in = new ByteArrayInputStream(bytes)) {
       ByteStreams.copy(in, out);
-    } finally {
-      in.close();
     }
   }
 
@@ -213,11 +210,8 @@
     res.setContentType("application/octet-stream");
     res.setContentLength((int) f.length());
     OutputStream out = res.getOutputStream();
-    InputStream in = new FileInputStream(f);
-    try {
+    try (InputStream in = new FileInputStream(f)) {
       ByteStreams.copy(in, out);
-    } finally {
-      in.close();
     }
   }
 
@@ -230,11 +224,8 @@
   private void streamRequestToFile(HttpServletRequest req, File file)
       throws IOException, FileNotFoundException {
     InputStream in = req.getInputStream();
-    OutputStream out = new FileOutputStream(file);
-    try {
+    try (OutputStream out = new FileOutputStream(file)) {
       ByteStreams.copy(in, out);
-    } finally {
-      out.close();
     }
   }
 }