ActivityChooser view not handling its removal and relayout properly.

1. ActivityChooserView did not hide the popup window when detached.

bug:6544220

2. ActivityChooserView was calling show popup when it was already
   showing it resulting in an incrrect update and losing one item
   per rotation.

bug:6522041

Change-Id: Iec1682ca5d27e38caf57214fa86060edf82a2166