Cannot use <SslContext> tag in blueprint configuration

Couldn't use the <SslContext> tag in blueprint configuration: setting a string attribute of the SslContext element resulted in the error "Cannot convert String to Spring Resource type" when I tried to use it in a blueprint file. It turns out that the Java source defines the property to be of Spring Resource type, not String.
Pulling the Resource type out of the api and pushing it into the implementations will keep the schema String type matching the api which is more natural and will work easily with blueprint.