title: No version of NDK matched the requested version
body: <p>After updating to <strong>Android Gradle plugin</strong> <code>3.6.0</code> (released Feb 24, 2020), several project independently started failing with:</p>
  
  <pre><code>No version of NDK matched the requested version 20.0.5594570. Versions available locally: 21.0.6113669
  </code></pre>
  
  <p>It's quite simple to "fix" this locally by installing the older expected ndk version:</p>
  
  <pre><code>sdkmanager 'ndk;20.0.5594570'
  </code></pre>
  
  <p>However, my question is: Where and how is this older version specified? And how do I update it so it matches the latest version <code>21.0.6113669</code>?</p>