Showcase: Update SDK to 23 and support lib to 23.0.1

Updated for new API addAsRoot() for GuidedStepFragment.
Rmove the awkward setStep() call,  we can find current GuidedStepFragment
using standard API.

Change-Id: I7ecb108a36ab5d0091c230dd5c5686e3a91f1857
7 files changed