TaskView - add a getter for the bitmap data.

This allows other components to get it directly from the view, rather
than retaining their own copy.

Bug: 137129923
Tested: Manual

Change-Id: Ibab307517c31cd3cb59b4d77ff390fd97546e86d

quickstep/recents_ui_overrides/src/com/android/quickstep/views/TaskThumbnailView.java

@@ -410,4 +410,11 @@ public class TaskThumbnailView extends View {
 
         return new ColorMatrixColorFilter(COLOR_MATRIX);
     }
+
+    public Bitmap getThumbnail() {
+        if (mThumbnailData == null) {
+            return null;
+        }
+        return mThumbnailData.thumbnail;
+    }
 }