Fix warnings about misuse of generic types

Change-Id: I3bede6adb3b7c9a5dec4cd07490a09c782db7e61
diff --git a/src/main/java/com/google/gerrit/common/Container.java b/src/main/java/com/google/gerrit/common/Container.java
index 62b672a..eb0a0f6 100644
--- a/src/main/java/com/google/gerrit/common/Container.java
+++ b/src/main/java/com/google/gerrit/common/Container.java
@@ -45,7 +45,7 @@
 
   @Override
   public int hashCode() {
-    List values = new ArrayList();
+    List<Object> values = new ArrayList<>();
     try {
       for (Field field : getClass().getDeclaredFields()) {
         field.setAccessible(true);
diff --git a/src/main/java/com/googlesource/gerrit/plugins/task/TaskAttributeFactory.java b/src/main/java/com/googlesource/gerrit/plugins/task/TaskAttributeFactory.java
index cb4d696..5045613 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/task/TaskAttributeFactory.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/task/TaskAttributeFactory.java
@@ -15,7 +15,6 @@
 package com.googlesource.gerrit.plugins.task;
 
 import com.google.gerrit.extensions.common.PluginDefinedInfo;
-import com.google.gerrit.index.query.Matchable;
 import com.google.gerrit.index.query.Predicate;
 import com.google.gerrit.index.query.QueryParseException;
 import com.google.gerrit.server.query.change.ChangeData;
@@ -292,7 +291,7 @@
       pred = cqb.parse(query);
       predicatesByQuery.put(query, pred);
     }
-    return ((Matchable) pred).match(c);
+    return pred.asMatchable().match(c);
   }
 
   protected Boolean matchOrNull(ChangeData c, String query) {
@@ -301,7 +300,7 @@
         if (query.equalsIgnoreCase("true")) {
           return true;
         }
-        return ((Matchable) cqb.parse(query)).match(c);
+        return cqb.parse(query).asMatchable().match(c);
       } catch (OrmException | QueryParseException e) {
       }
     }