am 20583ff9: Fix issue #2015611: layering problem when moving an activity to the foreground.

Merge commit '20583ff9d49257bd4ccc60e7b6337661e34ed887'

* commit '20583ff9d49257bd4ccc60e7b6337661e34ed887':
  Fix issue #2015611: layering problem when moving an activity to the foreground.