title: Windows subsystem WSL Ubuntu upgrade 18.04 to 20.04 issue
body: <p>For a windows subsystem WSL2,I upgraded a ubuntu 18.04 to ubuntu 20.08</p>
  <p>The upgrade command</p>
  <pre><code>sudo do-release-upgrade
  </code></pre>
  <p>After the installation</p>
  <pre><code>lsb_release -a
  No LSB modules are available.
  Distributor ID: Ubuntu
  Description:    Ubuntu 20.04.1 LTS
  Release:        20.04
  Codename:       focal
  </code></pre>
  <p>But at the windows command prompt</p>
  <pre><code>wsl -l -v
    NAME                   STATE           VERSION
  * Ubuntu-18.04           Running         2
    docker-desktop         Running         2
    docker-desktop-data    Running         2
  </code></pre>
  <p>I expected wsl to recognize the upgrade from ubuntu 18 to 20</p>
  <p>How do i correct <code>wsl -l -v</code> to reflect ubuntu 20.04</p>