Initial commit for Fingerprint Dialog sample based on the EAP sample.

Changed to:
- Conform to the DevRel template
- Introduced Dagger injection to make it testable
- Handle the case when the user hasn't set up a fingerptin or a lock screen
  to fall back to showing a message instead of the app crash
  - Some minor refactoring

  TODO Add InstrumentationTests once it can be launched.
  At this moment it can't be launched saying different API
  (E.g. Skipping device 'Nexus 5 - MNC', due to different API preview 'MNC' and
  'android-MNC')

  (Taken over from this CL ag/687121, since it turns out the branch for
  developers samples should be in mnc-preview-docs)

  Bug:19503196
  Bug:20765408
  Bug:21030545

Change-Id: I86180af66241ec3d463c75a0107239a7e6ac2e25
41 files changed