am c3daed96: Merge "docs: platform updates for api 21" into lmp-docs

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  <p><a href="#" onclick="return toggleContent(this)">

    <img src="{@docRoot}assets/images/triangle-opened.png"

class="toggle-content-img" alt="" />Revision 2</a> <em>(December 2014)</em>

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  <div class="toggle-content-toggleme">

    <p>Updated layouts in the Support Library and fixed various issues.</p>

    <p>Dependencies:</p>

    <ul>

      <li>Android SDK Platform-tools r21 or higher is required.</li>

      <li>Android SDK Tools 23.0.5 or higher is required.</li>

    </ul>

  </div>

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  <p><a href="#" onclick="return toggleContent(this)">

    <img src="{@docRoot}assets/images/triangle-closed.png"

class="toggle-content-img" alt="" />Revision 1</a> <em>(October 2014)</em>

  </p>