public TimestampFormatTrait.Format getDefaultTimestampFormat() {
        return defaultTimestampFormat;
    }
Uses the value of the jsonName trait when creating JSON schema
properties for structure and union shapes.

<p>This property has no effect if a {@link PropertyNamingStrategy} is
manually configured on a {@link JsonSchemaConverter}.

@param useJsonName Set to true to use jsonName traits when creating refs..
smithy-jsonschema/src/main/java/software/amazon/smithy/jsonschema/JsonSchemaConfig.java