title: @RawValue annotation is not applicable to target value parameter
body: <p>I am trying to <code>Parcelize</code> a data class.
  It contains one parameter :</p>
  <pre><code>var tokenType: Any? = null
  </code></pre>
  <p>For this variable compiler complains at compile time that :</p>
  <pre><code>Type is not directly supported by Parcelize. 
  Annotate the parameter with @RawValue if you want it to be serialized via 
  writeValue()
  </code></pre>
  <p>Though the error is self-explanatory, when I add @RawValue like this:</p>
  <pre><code>@RawValue var tokenType: Any? = null
  </code></pre>
  <p>it gives an error :</p>
  <pre><code>This annotation is not applicable to the target value parameter
  </code></pre>
  <p>Any hints on how to handle this?</p>