TalkBack doesn't announce when a task has being closed.

Adding announceForAccessibility() in createTaskDismissAnimation()
to announce the task has being closed.

Test: Manually tested
Fix: 186744160
Change-Id: I71f57e7ba03a61b2ced7e338da4251637e89bd16
diff --git a/quickstep/res/values/strings.xml b/quickstep/res/values/strings.xml
index 151b8e4..e10273c 100644
--- a/quickstep/res/values/strings.xml
+++ b/quickstep/res/values/strings.xml
@@ -39,6 +39,9 @@
     <!-- Accessibility title for the list of recent apps [CHAR_LIMIT=none] -->
     <string name="accessibility_recent_apps">Recent apps</string>
 
+    <!-- Accessibility confirmation for task closed -->
+    <string name="task_view_closed">Task Closed</string>
+
     <!-- Accessibility title for an app card in Recents for apps that have time limit set
      [CHAR_LIMIT=none] -->
     <string name="task_contents_description_with_remaining_time"><xliff:g id="task_description" example="GMail">%1$s</xliff:g>, <xliff:g id="remaining_time" example="7 minutes left today">%2$s</xliff:g></string>
diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index c065851..1c948ab 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -2740,6 +2740,8 @@
             }
         }
 
+        announceForAccessibility(getResources().getString(R.string.task_view_closed));
+
         float dismissTranslationInterpolationEnd = 1;
         boolean closeGapBetweenClearAll = false;
         boolean isClearAllHidden = isClearAllHidden();