ListProjects: Fix operator precedence warning raised by ErrorProne

Add grouping parenthesis to make the operator precedence explicit.

See http://errorprone.info/bugpattern/OperatorPrecedence

Change-Id: I8a0853f8fac05218e77e1a94ebff989380246d37

gerrit-server/src/main/java/com/google/gerrit/server/project/ListProjects.java

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/ListProjects.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/ListProjects.java
index 8c906ca..eeabac8 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/ListProjects.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/ListProjects.java
@@ -524,9 +524,9 @@
     try (Repository git = repoManager.openRepository(projectName)) {
       for (int i = 0; i < showBranch.size(); i++) {
         Ref ref = git.findRef(showBranch.get(i));
-        if (ref != null
+        if ((ref != null
                 && ref.getObjectId() != null
-                && (projectControl.controlForRef(ref.getLeaf().getName()).isVisible())
+                && (projectControl.controlForRef(ref.getLeaf().getName()).isVisible()))
             || (all && projectControl.isOwner())) {
           result[i] = ref;
         }