bug 347826138 clean up the deprecated region attribute custom_attribute_filter_multi_attributes (#9391)

Author: gotochkin

jobs/v3/src/main/java/com/google/samples/CustomAttributeSample.java

@@ -148,7 +148,6 @@ public static void filtersOnLongValueCustomAttribute() throws IOException, Inter
   // [END custom_attribute_filter_long_value]
 
   // [START job_custom_attribute_filter_multi_attributes]
-  // [START custom_attribute_filter_multi_attributes]
 
   /** CustomAttributeFilter on multiple CustomAttributes */
   public static void filtersOnMultiCustomAttributes() throws IOException, InterruptedException {
@@ -181,7 +180,6 @@ public static void filtersOnMultiCustomAttributes() throws IOException, Interrup
     Thread.sleep(1000);
     System.out.printf("Custom search job results (multiple value): %s\n", response);
   }
-  // [END custom_attribute_filter_multi_attributes]
   // [END job_custom_attribute_filter_multi_attributes]
 
   public static void main(String... args) throws Exception {