[JAVA] Javadoc backslash escape issue

Description

When codegen renders a method description into a Javadoc comment it seems to not correctly remove \"escapes.

Sample

"description":"Test\nRequires user permission: \"system.variables-rest:view\"."

Result:

     * Test  Requires user permission: \"system.variables-rest:view\".

It does not preserve the linebreaks and it does preserve the \

Swagger-codegen version

2.2.3

Swagger declaration file content or url

    "description":"Test\nRequires user permission: \"system.variables-rest:view\"."

Command line used for generation

java -jar ... generate -l java -i swagger.json -o .