Fix naming

Author: kamalaboulhosn

samples/snippets/src/main/java/pubsub/SubscribeAsyncUnlimitedConcurrencyExample.java

@@ -31,7 +31,7 @@
 public class SubscribeAsyncUnlimitedConcurrencyExample {
   public static void main(String... args) throws Exception {
     // TODO(developer): Replace these variables before running the sample.
-    String projectId = "my-topic";
+    String projectId = "my-project";
     String subscriptionId = "my-subscription";
 
     subscribeAsyncUnlimitedConcurrencyExample(projectId, subscriptionId);