commit ab90a18e2f05c7ae4158b770a9fbe9cbe4544597
author Andrew Lee <anwlee@google.com> Tue Sep 01 17:59:10 2015 -0700
committer Andrew Lee <anwlee@google.com> Tue Sep 01 18:22:49 2015 -0700
tree 8582caa28ef33d2ed89b090ccf9357c015da26ac
parent 0599e880630892becf1a1991e6712e0e6d9df3c8

Genericize promo card.

+ Make ViewHolder generic to generic to promo cards with customized
text or graphic layouts, as long as they implement two actions,
now designated the primary and secondary action views. This resuses
code which is logically similar between promo cards, and hopefully
doesn't bite us back in the future if there is a divergence in promo
card structure.

+ Make the GroupingListAdapter slightly "safer".

Bug: 23422274
Change-Id: I60bced4dbc61fec2e225a1cae9726ac40ed679a5