Merge "Fixing a flake when workspace loading never finishes." into udc-dev am: 5fe61d4ff7

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/23493702

Change-Id: Ibea27d3a0fc0cf4efc94fc0b651dd6ecf409fd91
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

src/com/android/launcher3/util/ViewOnDrawExecutor.java

@@ -59,6 +59,7 @@ public class ViewOnDrawExecutor implements OnDrawListener, Runnable,
     private void attachObserver() {
         if (!mCompleted) {
             mAttachedView.getViewTreeObserver().addOnDrawListener(this);
+            mAttachedView.getRootView().invalidate();
         }
     }