Make isVisible member in TaskInfo public for digital wellbeing

Bug: 199825187
Test: N/A
Change-Id: If2e8ff32e865591ea8b2de68e5cb1e8b05e06f35

core/api/current.txt

@@ -6711,6 +6711,7 @@ package android.app {
   }
 
   public class TaskInfo {
+    method public boolean isVisible();
     field @Nullable public android.content.ComponentName baseActivity;
     field @NonNull public android.content.Intent baseIntent;
     field public boolean isRunning;

core/java/android/app/TaskInfo.java

@@ -264,6 +264,13 @@ public class TaskInfo {
         readFromParcel(source);
     }
 
+    /**
+     * Whether this task is visible.
+     */
+    public boolean isVisible() {
+        return isVisible;
+    }
+
     /**
      * @param isLowResolution
      * @return