chore(job): migrate region tag (GoogleCloudPlatform#9976)

* chore(job): migrate region tag

* chore(job): rename region tag

Author: alarconesparza

compute/mailjet/src/main/java/com/example/compute/mailjet/MailjetSender.java

@@ -16,7 +16,7 @@
 
 package com.example.compute.mailjet;
 
-// [START mailjet_imports]
+// [START compute_mailjet_imports]
 
 import com.mailjet.client.ClientOptions;
 import com.mailjet.client.MailjetClient;
@@ -27,8 +27,9 @@
 import org.json.JSONArray;
 import org.json.JSONObject;
 
-// [END mailjet_imports]
+// [END compute_mailjet_imports]
 
+// [START compute_mailjet_send_email]
 // [START app]
 public class MailjetSender {
 
@@ -82,3 +83,4 @@ public MailjetResponse sendMailjet(String recipient, String sender, MailjetClien
   }
 }
 // [END app]
+// [END compute_mailjet_send_email]