Fix dialog exit animation

This CL fixes a bug that could happen when animating a dialog out at the
same time as hiding the SystemUI shade, and that would make the phone
unusable until the shade is swiped down again. See b/223387276 for more
info.

Bug: 223387276
Test: Manual, see b/223387276#comment1
Change-Id: If251b00558a5ca9a927d1be2bb015f1c0acb2d57

core/java/android/view/ViewRootImpl.java

@@ -3390,6 +3390,12 @@ public final class ViewRootImpl implements ViewParent,
                     mReportNextDraw = false;
                     pendingDrawFinished();
                 }
+
+                // Make sure the consumer is not waiting if the view root was just made invisible.
+                if (mBLASTDrawConsumer != null) {
+                    mBLASTDrawConsumer.accept(null);
+                    mBLASTDrawConsumer = null;
+                }
             }
         }