Add new fragment demo for changing with config.

This changes the FragmentLayout demo to show how the layout
(and entire UI flow) can easily be changed based on screen configuration
using fragments.  Here we have different UI for landscape vs portrait.

The old FragmentLayout demo is renamed to FragmentAnim and extended a
bit.

Various other tweaks to follow fragment API changes.

Change-Id: I8df918dbf32b3617cae2b20f77eb37d8211b8c89
12 files changed