Fix crash in recents log when in Talkback mode.

Views are null because of how tags are set with the new ViewHolder
logic. In the long run, I expect all this logic will be obsolete
once we listen to changes on individual ViewHolders. Presumably,
at that point, we don't need to deal with all this tag business.

Bug: 20521104
Change-Id: Iaf7aff6f576a0a5c097acbd461c7a1d88c932231