Add round/notround qualifier to docs

which indicates whether the screen is long.</p>

      </td>

    </tr>

    <tr id="ScreenRoundQualifier">

      <td>Round screen</td>

      <td>

        <code>round</code><br/>

        <code>notround</code>

      </td>

      <td>

        <ul class="nolist">

          <li>{@code round}: Round screens, such as a round wearable device</li>

          <li>{@code notround}: Rectangular screens, such as phones or tablets</li>

        </ul>

        <p><em>Added in API level 23.</em></p>

        <p>Also see the {@link android.content.res.Configuration#isScreenRound()} configuration

method, which indicates whether the screen is round.</p>

      </td>

    </tr>

    <tr id="OrientationQualifier">

      <td>Screen orientation</td>

      <td>