Merge "Adding a link to what is currently our most popular "100 Days" video." into mnc-preview-docs

<uses-permission

        android:name="android.permission.USE_FINGERPRINT" />

</pre>

<img src="{@docRoot}preview/images/fingerprint-screen.png"

srcset="{@docRoot}preview/images/fingerprint-screen.png 1x, {@docRoot}preview/images/fingerprint-screen_2x.png 2x"

style="float:right; margin:0 0 10px 20px" width="282" height="476" />

<p>To see an app implementation of fingerprint authentication, refer to the

<a href="https://github.com/googlesamples/android-FingerprintDialog" class="external-link">

  Fingerprint Dialog sample</a>.</p>

  Fingerprint Dialog sample</a>. For a demonstration of how you can use these authentication

  APIs in conjunction with other Android APIs, see the video

  <a class="video-shadowbox-button" href="https://www.youtube.com/watch?v=VOn7VrTRlA4">

  Fingerprint and Payment APIs</a>.</p>

<p>If you are testing this feature, follow these steps:</p>

<ol>