Create OOBE screen for Voice Interaction value proposition

- Add a new OOBE screen for Voice Interaction value prop, which will
  show up after user image selection on the first run.
- If user clicks "No Thanks", chromeos tutorial app will be launched
- If user clicks "Continue", an intent to launch Voice Interaction
  setup wizard will be fired.

BUG=b/38197377
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2912593002
Cr-Commit-Position: refs/heads/master@{#477864}
45 files changed