libgoogle-gson-java binary package in Ubuntu Focal amd64

 Gson is a Java library that can be used to convert Java Objects into their JSON
 representation. It can also be used to convert a JSON string to an equivalent
 Java object. Gson can work with arbitrary Java objects including pre-existing
 objects that you do not have source-code of.
 .
 Gson Goals
 .
  * Provide simple toJson() and fromJson() methods to convert Java objects to
    JSON and vice-versa
  * Allow pre-existing unmodifiable objects to be converted to and from JSON
  * Extensive support of Java Generics
  * Allow custom representations for objects
  * Support arbitrarily complex objects (with deep inheritance hierarchies and
    extensive use of generic types)

Source package