We may be stopped, removed from the view hierarchy, and then only
attached again after the activity has been restarted, missing
our WindowStopped callback to set mWindowStopped=false. At this point
we are being added to a visible view, or in ViewRoot#performTraversals
so we can assume we are not stopped.
Test: Manual from bug.
Bug: 37682805
Change-Id: Idf8e061fb7f83b00992a274c7dd704f9e0fcff5f