How to externalise sslContextParameters

I'm using Apache Camel 2.20.0 and deploying a REST service using REST DSL with a HTTP scheme.

I'm referencing sslContextParameters with hard coded values and all works just fine.

I can't find a way of externalizing the resource into a properties file. So far I've tried with Camel PropertiesComponent and also Spring PropertyPlaceholderConfigurer and BridgePropertyPlaceholderConfigurer and I want to be able to do the following in the config:

<camel:sslContextParameters camelContextId="camelContext1" id="routeSSLContextParameters">
    <camel:keyManagers keyPassword="{{mypassword}}">
        <camel:keyStore password="{{mypassword}}"
            resource="{{mykeystore}}" type="JKS"/>
    </camel:keyManagers>
    <camel:trustManagers>
        <camel:keyStore password="{{mypassword}}"
            resource="{{mykeystore}}" type="JKS"/>
    </camel:trustManagers>
</camel:sslContextParameters>

I've also tried putting ${} as per Spring properties, this also does not work.

Would it be possible to tell me where I'm going wrong?