Remove reference to obsolete installation step.

<p>To install and configure the NDK, follow these steps:</p>

<ol type="1">

<li>Get and install the <a href="{@docRoot}studio/index.html">Android SDK</a>.</li>

<li><a href="{@docRoot}ndk/downloads/index.html">Download</a> and

<a href="{@docRoot}ndk/downloads/index.html#extract">extract</a> the NDK,

<li><a href="{@docRoot}ndk/downloads/index.html">Download</a> the NDK,

making sure to download the correct version for your development platform. You may place the

unzipped directory anywhere on your local drive.</li>

<li>Update your {@code PATH} environment variable with the location of the directory that