ActivityChooserView not showing "Show all" properly if the default target button not shown.

If the default target button is hidden all activities are shown in the list from
which to choose. In this case due to off by one error the list was not showing the
option to expand it if the activities are one more than the initially shown.

bug:5358475

Change-Id: I8c3db37dab008637d78330f8de830cec92720264