Launcher3: Ensure to update cached thumbnail if we take new one

This fixes a bug, which became obvious thanks to disabled live tile, but
has already existed before, where recents jumps to using last snapshot
instead of the correct/current one once you fling, because thumbnails
were cached but the cache had not been updated in this codepath.

Change-Id: Ie7afe56b6e0aecaae2510248c5887873800a0b51

quickstep/src/com/android/quickstep/views/RecentsView.java

@@ -5619,6 +5619,7 @@ public abstract class RecentsView<ACTIVITY_TYPE extends StatefulActivity<STATE_T
                     mRecentsAnimationController.screenshotTask(container.getTask().key.id);
             TaskThumbnailView thumbnailView = container.getThumbnailView();
             if (td != null) {
+                container.getTask().thumbnail = td;
                 thumbnailView.setThumbnail(container.getTask(), td);
             } else {
                 thumbnailView.refresh();