Increase SAAS WorkerScheduler WorkerPartition AcknowledgementSet timeout to 2 hours (opensearch-project#6298)

*What?**

This commit incerases SAAS worker partition AcknowledgementSet timeout from 20 seconds
to 2 hours.

**Why?**

20 seconds is not enough for finish processing each worker partition. Increase it to infinite
high to ensure each worker partition has enough time for processing.

Signed-off-by: Wenjie Yao <wjyao@amazon.com>
Co-authored-by: Wenjie Yao <wjyao@amazon.com>

Author: wjyao0316

data-prepper-plugins/saas-source-plugins/source-crawler/src/main/java/org/opensearch/dataprepper/plugins/source/source_crawler/coordination/scheduler/WorkerScheduler.java

@@ -32,7 +32,7 @@ public class WorkerScheduler implements Runnable {
     public static final String WORKER_PARTITIONS_FAILED = "workerPartitionsFailed";
     public static final String WORKER_PARTITIONS_COMPLETED = "workerPartitionsCompleted";
 
-    private static final Duration ACKNOWLEDGEMENT_SET_TIMEOUT = Duration.ofSeconds(20);
+    private static final Duration ACKNOWLEDGEMENT_SET_TIMEOUT = Duration.ofHours(2);
     private static final Logger log = LoggerFactory.getLogger(WorkerScheduler.class);
     private static final int RETRY_BACKOFF_ON_EXCEPTION_MILLIS = 5_000;
     private static final Duration DEFAULT_SLEEP_DURATION_MILLIS = Duration.ofMillis(10000);