Fix: Prevent startForeground crash and TransferService stopping while transfers ongoing (#2961)

* Awlays call startForeground, even if notification already shown

* Break is in the wrong place and couild cause transfer service to get killed when it shouldn't

* Only stop transfer service on Android versions that show Foreground Notification

Author: tylerjroach

aws-android-sdk-s3/src/main/java/com/amazonaws/mobileconnectors/s3/transferutility/TransferService.java

@@ -53,11 +53,6 @@ public class TransferService extends Service {
      */
     boolean isReceiverNotRegistered = true;
 
-    /**
-     * A flag that indicates whether or not the Foreground notification started
-     */
-    boolean hasNotificationShown = false;
-
     /**
      * The identifier used for the notification.
      */
@@ -142,8 +137,7 @@ public int onStartCommand(Intent intent, int flags, int startId) {
          * b) An identifier for the ongoing notification c) Flag that determines if the notification
          * needs to be removed when the service is moved out of the foreground state.
          */
-        if (Build.VERSION.SDK_INT >= ANDROID_OREO && !hasNotificationShown) {
-            hasNotificationShown = true;
+        if (Build.VERSION.SDK_INT >= ANDROID_OREO) {
             try {
                 synchronized (this) {
                     final Notification userProvidedNotification = (Notification) intent.getParcelableExtra(INTENT_KEY_NOTIFICATION);

aws-android-sdk-s3/src/main/java/com/amazonaws/mobileconnectors/s3/transferutility/TransferStatusUpdater.java

@@ -17,6 +17,7 @@
 
 import android.content.Context;
 import android.content.Intent;
+import android.os.Build;
 import android.os.Handler;
 import android.os.Looper;
 
@@ -246,17 +247,19 @@ public void run() {
 
         // If all transfers in local map are completed,
         // stop TransferService to clear foreground notification
-        boolean stopTransferService = true;
-        for (TransferRecord record: transfers.values()) {
-            if (!TransferState.isFinalState(record.state)) {
-                stopTransferService = false;
-                LOGGER.info("Transfers still pending, keeping TransferService running.");
+        if (Build.VERSION.SDK_INT >= 26) {
+            boolean stopTransferService = true;
+            for (TransferRecord record : transfers.values()) {
+                if (!TransferState.isFinalState(record.state)) {
+                    stopTransferService = false;
+                    LOGGER.info("Transfers still pending, keeping TransferService running.");
+                    break;
+                }
+            }
+            if (stopTransferService) {
+                LOGGER.info("All transfers in final state. Stopping TransferService");
+                context.stopService(new Intent(context, TransferService.class));
             }
-            break;
-        }
-        if (stopTransferService) {
-            LOGGER.info("All transfers in final state. Stopping TransferService");
-            context.stopService(new Intent(context, TransferService.class));
         }
     }