How to keep a configuration file when on upgrade but remove it on uninstall?

Question

I want to keep a config file when on upgrading but remove it on uninstalling.

<Directory Id="CommonAppDataFolder">
        <Directory Id="dir_99306542_9959_46A2_9928_91FA5A0112C0" Name="ProofpointPlugin">          
          <Component Id="comp_22FC069D_8417_4504_9F0F_4F01DD04C6C8" Guid="E0CC1916-F33F-48DC-8677-5FF077722114">
            <RemoveFile Id="remove_config_file" Name="config.json" On="uninstall"/>
            <Condition>(REMOVE=ALL) AND (NOT UPGRADINGPRODUCTCODE)</Condition>
          </Component>
        </Directory>
      </Directory>

And I have this to facilitate upgrades

<RemoveExistingProducts After='InstallInitialize'></RemoveExistingProducts>